7
(The current version of this document is available in the file
8
``doc/developers/HACKING.txt`` in the source tree, or at
9
http://doc.bazaar-vcs.org/bzr.dev/en/developer-guide/HACKING.html)
15
Exploring the Bazaar Platform
16
=============================
18
Before making changes, it's a good idea to explore the work already
19
done by others. Perhaps the new feature or improvement you're looking
20
for is available in another plug-in already? If you find a bug,
21
perhaps someone else has already fixed it?
23
To answer these questions and more, take a moment to explore the
24
overall Bazaar Platform. Here are some links to browse:
26
* The Plugins page on the Wiki - http://bazaar-vcs.org/BzrPlugins
28
* The Bazaar product family on Launchpad - https://launchpad.net/bazaar
30
* Bug Tracker for the core product - https://bugs.launchpad.net/bzr/
32
* Blueprint Tracker for the core product - https://blueprints.launchpad.net/bzr/
34
If nothing else, perhaps you'll find inspiration in how other developers
35
have solved their challenges.
38
Planning and Discussing Changes
39
===============================
41
There is a very active community around Bazaar. Mostly we meet on IRC
42
(#bzr on irc.freenode.net) and on the mailing list. To join the Bazaar
43
community, see http://bazaar-vcs.org/BzrSupport.
45
If you are planning to make a change, it's a very good idea to mention it
46
on the IRC channel and/or on the mailing list. There are many advantages
47
to involving the community before you spend much time on a change.
50
* you get to build on the wisdom on others, saving time
52
* if others can direct you to similar code, it minimises the work to be done
54
* it assists everyone in coordinating direction, priorities and effort.
56
In summary, maximising the input from others typically minimises the
57
total effort required to get your changes merged. The community is
58
friendly, helpful and always keen to welcome newcomers.
61
Bazaar Development in a Nutshell
62
================================
64
Looking for a 10 minute introduction to submitting a change?
65
See http://bazaar-vcs.org/BzrGivingBack.
67
TODO: Merge that Wiki page into this document.
70
Understanding the Development Process
71
=====================================
73
The development team follows many best-practices including:
75
* a public roadmap and planning process in which anyone can participate
77
* time based milestones everyone can work towards and plan around
79
* extensive code review and feedback to contributors
81
* complete and rigorous test coverage on any code contributed
83
* automated validation that all tests still pass before code is merged
84
into the main code branch.
86
The key tools we use to enable these practices are:
88
* Launchpad - https://launchpad.net/
90
* Bazaar - http://bazaar-vcs.org/
92
* Bundle Buggy - http://bundlebuggy.aaronbentley.com/
94
* Patch Queue Manager - https://launchpad.net/pqm/
96
For further information, see http://bazaar-vcs.org/BzrDevelopment.
99
A Closer Look at the Merge & Review Process
100
===========================================
102
If you'd like to propose a change, please post to the
103
bazaar@lists.canonical.com list with a bundle, patch, or link to a
104
branch. Put '[PATCH]' or '[MERGE]' in the subject so Bundle Buggy
105
can pick it out, and explain the change in the email message text.
106
Remember to update the NEWS file as part of your change if it makes any
107
changes visible to users or plugin developers. Please include a diff
108
against mainline if you're giving a link to a branch.
110
You can generate a bundle like this::
112
bzr bundle > mybundle.patch
114
A .patch extension is recommended instead of .bundle as many mail clients
115
will send the latter as a binary file. If a bundle would be too long or your
116
mailer mangles whitespace (e.g. implicitly converts Unix newlines to DOS
117
newlines), use the merge-directive command instead like this::
119
bzr merge-directive http://bazaar-vcs.org http://example.org/my_branch > my_directive.patch
121
See the help for details on the arguments to merge-directive.
123
Please do **NOT** put [PATCH] or [MERGE] in the subject line if you don't
124
want it to be merged. If you want comments from developers rather than
125
to be merged, you can put '[RFC]' in the subject line.
127
Anyone is welcome to review code. There are broadly three gates for
130
* Doesn't reduce test coverage: if it adds new methods or commands,
131
there should be tests for them. There is a good test framework
132
and plenty of examples to crib from, but if you are having trouble
133
working out how to test something feel free to post a draft patch
136
* Doesn't reduce design clarity, such as by entangling objects
137
we're trying to separate. This is mostly something the more
138
experienced reviewers need to help check.
140
* Improves bugs, features, speed, or code simplicity.
142
Code that goes in should pass all three. The core developers take care
143
to keep the code quality high and understandable while recognising that
144
perfect is sometimes the enemy of good. (It is easy for reviews to make
145
people notice other things which should be fixed but those things should
146
not hold up the original fix being accepted. New things can easily be
147
recorded in the Bug Tracker instead.)
149
Anyone can "vote" on the mailing list. Core developers can also vote using
150
Bundle Buggy. Here are the voting codes and their explanations.
152
:approve: Reviewer wants this submission merged.
153
:tweak: Reviewer wants this submission merged with small changes. (No
155
:abstain: Reviewer does not intend to vote on this patch.
156
:resubmit: Please make changes and resubmit for review.
157
:reject: Reviewer doesn't want this kind of change merged.
158
:comment: Not really a vote. Reviewer just wants to comment, for now.
160
If a change gets two approvals from core reviewers, and no rejections,
161
then it's OK to come in. Any of the core developers can bring it into the
162
bzr.dev trunk and backport it to maintenance branches if required. The
163
Release Manager will merge the change into the branch for a pending
164
release, if any. As a guideline, core developers usually merge their own
165
changes and volunteer to merge other contributions if they were the second
166
reviewer to agree to a change.
168
To track the progress of proposed changes, use Bundle Buggy. See
169
http://bundlebuggy.aaronbentley.com/help for a link to all the
170
outstanding merge requests together with an explanation of the columns.
171
Bundle Buggy will also mail you a link to track just your change.
174
Preparing a Sandbox for Making Changes to Bazaar
175
================================================
177
Bazaar supports many ways of organising your work. See
178
http://bazaar-vcs.org/SharedRepositoryLayouts for a summary of the
179
popular alternatives.
181
Of course, the best choice for you will depend on numerous factors:
182
the number of changes you may be making, the complexity of the changes, etc.
183
As a starting suggestion though:
185
* create a local copy of the main development branch (bzr.dev) by using
188
bzr branch http://bazaar-vcs.org/bzr/bzr.dev/ bzr.dev
190
* keep your copy of bzr.dev prestine (by not developing in it) and keep
191
it up to date (by using bzr pull)
193
* create a new branch off your local bzr.dev copy for each issue
194
(bug or feature) you are working on.
196
This approach makes it easy to go back and make any required changes
197
after a code review. Resubmitting the change is then simple with no
198
risk of accidentially including edits related to other issues you may
199
be working on. After the changes for an issue are accepted and merged,
200
the associated branch can be deleted or archived as you wish.
203
Navigating the Code Base
204
========================
206
TODO: List and describe in one line the purpose of each directory
207
inside an installation of bzr.
209
TODO: Refer to a central location holding an up to date copy of the API
210
documentation generated by epydoc, e.g. something like
211
http://starship.python.net/crew/mwh/bzrlibapi/bzrlib.html.
217
The Importance of Testing
218
=========================
220
Reliability is a critical success factor for any Version Control System.
221
We want Bazaar to be highly reliable across multiple platforms while
222
evolving over time to meet the needs of its community.
224
In a nutshell, this is want we expect and encourage:
226
* New functionality should have test cases. Preferably write the
227
test before writing the code.
229
In general, you can test at either the command-line level or the
230
internal API level. See Writing tests below for more detail.
232
* Try to practice Test-Driven Development: before fixing a bug, write a
233
test case so that it does not regress. Similarly for adding a new
234
feature: write a test case for a small version of the new feature before
235
starting on the code itself. Check the test fails on the old code, then
236
add the feature or fix and check it passes.
238
By doing these things, the Bazaar team gets increased confidence that
239
changes do what they claim to do, whether provided by the core team or
240
by community members. Equally importantly, we can be surer that changes
241
down the track do not break new features or bug fixes that you are
244
As of May 2007, Bazaar ships with a test suite containing over 6000 tests
245
and growing. We are proud of it and want to remain so. As community
246
members, we all benefit from it. Would you trust version control on
247
your project to a product *without* a test suite like Bazaar has?
250
Running the Test Suite
251
======================
253
Currently, bzr selftest is used to invoke tests.
254
You can provide a pattern argument to run a subset. For example,
255
to run just the blackbox tests, run::
257
./bzr selftest -v blackbox
259
To skip a particular test (or set of tests), use the --exclude option
260
(shorthand -x) like so::
262
./bzr selftest -v -x blackbox
264
To ensure that all tests are being run and succeeding, you can use the
265
--strict option which will fail if there are any missing features or known
268
./bzr selftest --strict
270
To list tests without running them, use the --list-only option like so::
272
./bzr selftest --list-only
274
This option can be combined with other selftest options (like -x) and
275
filter patterns to understand their effect.
281
In general tests should be placed in a file named test_FOO.py where
282
FOO is the logical thing under test. That file should be placed in the
283
tests subdirectory under the package being tested.
285
For example, tests for merge3 in bzrlib belong in bzrlib/tests/test_merge3.py.
286
See bzrlib/tests/test_sampler.py for a template test script.
288
Tests can be written for the UI or for individual areas of the library.
289
Choose whichever is appropriate: if adding a new command, or a new command
290
option, then you should be writing a UI test. If you are both adding UI
291
functionality and library functionality, you will want to write tests for
292
both the UI and the core behaviours. We call UI tests 'blackbox' tests
293
and they are found in ``bzrlib/tests/blackbox/*.py``.
295
When writing blackbox tests please honour the following conventions:
297
1. Place the tests for the command 'name' in
298
bzrlib/tests/blackbox/test_name.py. This makes it easy for developers
299
to locate the test script for a faulty command.
301
2. Use the 'self.run_bzr("name")' utility function to invoke the command
302
rather than running bzr in a subprocess or invoking the
303
cmd_object.run() method directly. This is a lot faster than
304
subprocesses and generates the same logging output as running it in a
305
subprocess (which invoking the method directly does not).
307
3. Only test the one command in a single test script. Use the bzrlib
308
library when setting up tests and when evaluating the side-effects of
309
the command. We do this so that the library api has continual pressure
310
on it to be as functional as the command line in a simple manner, and
311
to isolate knock-on effects throughout the blackbox test suite when a
312
command changes its name or signature. Ideally only the tests for a
313
given command are affected when a given command is changed.
315
4. If you have a test which does actually require running bzr in a
316
subprocess you can use ``run_bzr_subprocess``. By default the spawned
317
process will not load plugins unless ``--allow-plugins`` is supplied.
323
We make selective use of doctests__. In general they should provide
324
*examples* within the API documentation which can incidentally be tested. We
325
don't try to test every important case using doctests -- regular Python
326
tests are generally a better solution.
328
Most of these are in ``bzrlib/doc/api``. More additions are welcome.
330
__ http://docs.python.org/lib/module-doctest.html
333
Skipping tests and test requirements
334
------------------------------------
336
In our enhancements to unittest we allow for some addition results beyond
337
just success or failure.
339
If a test can't be run, it can say that it's skipped. This is typically
340
used in parameterized tests - for example if a transport doesn't support
341
setting permissions, we'll skip the tests that relating to that. ::
344
return self.branch_format.initialize(repo.bzrdir)
345
except errors.UninitializableFormat:
346
raise tests.TestSkipped('Uninitializable branch format')
348
Raising TestSkipped is a good idea when you want to make it clear that the
349
test was not run, rather than just returning which makes it look as if it
352
Several different cases are distinguished:
355
Generic skip; the only type that was present up to bzr 0.18.
358
The test doesn't apply to the parameters with which it was run.
359
This is typically used when the test is being applied to all
360
implementations of an interface, but some aspects of the interface
361
are optional and not present in particular concrete
362
implementations. (Some tests that should raise this currently
363
either silently return or raise TestSkipped.) Another option is
364
to use more precise parameterization to avoid generating the test
368
**(Not implemented yet)**
369
The test can't be run because of an inherent limitation of the
370
environment, such as not having symlinks or not supporting
374
The test can't be run because a dependency (typically a Python
375
library) is not available in the test environment. These
376
are in general things that the person running the test could fix
377
by installing the library. It's OK if some of these occur when
378
an end user runs the tests or if we're specifically testing in a
379
limited environment, but a full test should never see them.
382
The test exists but is known to fail, for example because the
383
code to fix it hasn't been run yet. Raising this allows
384
you to distinguish these failures from the ones that are not
385
expected to fail. This could be conditionally raised if something
386
is broken on some platforms but not on others.
388
We plan to support three modes for running the test suite to control the
389
interpretation of these results. Strict mode is for use in situations
390
like merges to the mainline and releases where we want to make sure that
391
everything that can be tested has been tested. Lax mode is for use by
392
developers who want to temporarily tolerate some known failures. The
393
default behaviour is obtained by ``bzr selftest`` with no options, and
394
also (if possible) by running under another unittest harness.
396
======================= ======= ======= ========
397
result strict default lax
398
======================= ======= ======= ========
399
TestSkipped pass pass pass
400
TestNotApplicable pass pass pass
401
TestPlatformLimit pass pass pass
402
TestDependencyMissing fail pass pass
403
KnownFailure fail pass pass
404
======================= ======= ======= ========
407
Test feature dependencies
408
-------------------------
410
Rather than manually checking the environment in each test, a test class
411
can declare its dependence on some test features. The feature objects are
412
checked only once for each run of the whole test suite.
414
For historical reasons, as of May 2007 many cases that should depend on
415
features currently raise TestSkipped.)
419
class TestStrace(TestCaseWithTransport):
421
_test_needs_features = [StraceFeature]
423
This means all tests in this class need the feature. The feature itself
424
should provide a ``_probe`` method which is called once to determine if
427
These should generally be equivalent to either TestDependencyMissing or
428
sometimes TestPlatformLimit.
434
Known failures are when a test exists but we know it currently doesn't
435
work, allowing the test suite to still pass. These should be used with
436
care, we don't want a proliferation of quietly broken tests. It might be
437
appropriate to use them if you've committed a test for a bug but not the
438
fix for it, or if something works on Unix but not on Windows.
441
Testing exceptions and errors
442
-----------------------------
444
It's important to test handling of errors and exceptions. Because this
445
code is often not hit in ad-hoc testing it can often have hidden bugs --
446
it's particularly common to get NameError because the exception code
447
references a variable that has since been renamed.
449
.. TODO: Something about how to provoke errors in the right way?
451
In general we want to test errors at two levels:
453
1. A test in ``test_errors.py`` checking that when the exception object is
454
constructed with known parameters it produces an expected string form.
455
This guards against mistakes in writing the format string, or in the
456
``str`` representations of its parameters. There should be one for
457
each exception class.
459
2. Tests that when an api is called in a particular situation, it raises
460
an error of the expected class. You should typically use
461
``assertRaises``, which in the Bazaar test suite returns the exception
462
object to allow you to examine its parameters.
464
In some cases blackbox tests will also want to check error reporting. But
465
it can be difficult to provoke every error through the commandline
466
interface, so those tests are only done as needed -- eg in response to a
467
particular bug or if the error is reported in an unusual way(?) Blackbox
468
tests should mostly be testing how the command-line interface works, so
469
should only test errors if there is something particular to the cli in how
470
they're displayed or handled.
476
The Python ``warnings`` module is used to indicate a non-fatal code
477
problem. Code that's expected to raise a warning can be tested through
480
The test suite can be run with ``-Werror`` to check no unexpected errors
483
However, warnings should be used with discretion. It's not an appropriate
484
way to give messages to the user, because the warning is normally shown
485
only once per source line that causes the problem. You should also think
486
about whether the warning is serious enought that it should be visible to
487
users who may not be able to fix it.
490
Interface implementation testing and test scenarios
491
---------------------------------------------------
493
There are several cases in Bazaar of multiple implementations of a common
494
conceptual interface. ("Conceptual" because
495
it's not necessary for all the implementations to share a base class,
496
though they often do.) Examples include transports and the working tree,
497
branch and repository classes.
499
In these cases we want to make sure that every implementation correctly
500
fulfils the interface requirements. For example, every Transport should
501
support the ``has()`` and ``get()`` and ``clone()`` methods. We have a
502
sub-suite of tests in ``test_transport_implementations``. (Most
503
per-implementation tests are in submodules of ``bzrlib.tests``, but not
504
the transport tests at the moment.)
506
These tests are repeated for each registered Transport, by generating a
507
new TestCase instance for the cross product of test methods and transport
508
implementations. As each test runs, it has ``transport_class`` and
509
``transport_server`` set to the class it should test. Most tests don't
510
access these directly, but rather use ``self.get_transport`` which returns
511
a transport of the appropriate type.
513
The goal is to run per-implementation only tests that relate to that
514
particular interface. Sometimes we discover a bug elsewhere that happens
515
with only one particular transport. Once it's isolated, we can consider
516
whether a test should be added for that particular implementation,
517
or for all implementations of the interface.
519
The multiplication of tests for different implementations is normally
520
accomplished by overriding the ``test_suite`` function used to load
521
tests from a module. This function typically loads all the tests,
522
then applies a TestProviderAdapter to them, which generates a longer
523
suite containing all the test variations.
529
Some utilities are provided for generating variations of tests. This can
530
be used for per-implementation tests, or other cases where the same test
531
code needs to run several times on different scenarios.
533
The general approach is to define a class that provides test methods,
534
which depend on attributes of the test object being pre-set with the
535
values to which the test should be applied. The test suite should then
536
also provide a list of scenarios in which to run the tests.
538
Typically ``multiply_tests_from_modules`` should be called from the test
539
module's ``test_suite`` function.
542
Essential Domain Classes
543
########################
545
Introducing the Object Model
546
============================
548
The core domain objects within the bazaar model are:
558
Transports are explained below. See http://bazaar-vcs.org/Classes/
559
for an introduction to the other key classes.
564
The ``Transport`` layer handles access to local or remote directories.
565
Each Transport object acts like a logical connection to a particular
566
directory, and it allows various operations on files within it. You can
567
*clone* a transport to get a new Transport connected to a subdirectory or
570
Transports are not used for access to the working tree. At present
571
working trees are always local and they are accessed through the regular
572
Python file io mechanisms.
577
Transports work in URLs. Take note that URLs are by definition only
578
ASCII - the decision of how to encode a Unicode string into a URL must be
579
taken at a higher level, typically in the Store. (Note that Stores also
580
escape filenames which cannot be safely stored on all filesystems, but
581
this is a different level.)
583
The main reason for this is that it's not possible to safely roundtrip a
584
URL into Unicode and then back into the same URL. The URL standard
585
gives a way to represent non-ASCII bytes in ASCII (as %-escapes), but
586
doesn't say how those bytes represent non-ASCII characters. (They're not
587
guaranteed to be UTF-8 -- that is common but doesn't happen everywhere.)
589
For example if the user enters the url ``http://example/%e0`` there's no
590
way to tell whether that character represents "latin small letter a with
591
grave" in iso-8859-1, or "latin small letter r with acute" in iso-8859-2
592
or malformed UTF-8. So we can't convert their URL to Unicode reliably.
594
Equally problematic if we're given a url-like string containing non-ascii
595
characters (such as the accented a) we can't be sure how to convert that
596
to the correct URL, because we don't know what encoding the server expects
597
for those characters. (Although this is not totally reliable we might still
598
accept these and assume they should be put into UTF-8.)
600
A similar edge case is that the url ``http://foo/sweet%2Fsour`` contains
601
one directory component whose name is "sweet/sour". The escaped slash is
602
not a directory separator. If we try to convert URLs to regular Unicode
603
paths this information will be lost.
605
This implies that Transports must natively deal with URLs; for simplicity
606
they *only* deal with URLs and conversion of other strings to URLs is done
607
elsewhere. Information they return, such as from ``list_dir``, is also in
608
the form of URL components.
617
We have a commitment to 6 months API stability - any supported symbol in a
618
release of bzr MUST NOT be altered in any way that would result in
619
breaking existing code that uses it. That means that method names,
620
parameter ordering, parameter names, variable and attribute names etc must
621
not be changed without leaving a 'deprecated forwarder' behind. This even
622
applies to modules and classes.
624
If you wish to change the behaviour of a supported API in an incompatible
625
way, you need to change its name as well. For instance, if I add an optional keyword
626
parameter to branch.commit - that's fine. On the other hand, if I add a
627
keyword parameter to branch.commit which is a *required* transaction
628
object, I should rename the API - i.e. to 'branch.commit_transaction'.
630
When renaming such supported API's, be sure to leave a deprecated_method (or
631
_function or ...) behind which forwards to the new API. See the
632
bzrlib.symbol_versioning module for decorators that take care of the
633
details for you - such as updating the docstring, and issuing a warning
634
when the old api is used.
636
For unsupported API's, it does not hurt to follow this discipline, but it's
637
not required. Minimally though, please try to rename things so that
638
callers will at least get an AttributeError rather than weird results.
641
Deprecation decorators
642
----------------------
644
``bzrlib.symbol_versioning`` provides decorators that can be attached to
645
methods, functions, and other interfaces to indicate that they should no
648
To deprecate a static method you must call ``deprecated_function``
649
(**not** method), after the staticmethod call::
652
@deprecated_function(zero_ninetyone)
653
def create_repository(base, shared=False, format=None):
655
When you deprecate an API, you should not just delete its tests, because
656
then we might introduce bugs in them. If the API is still present at all,
657
it should still work. The basic approach is to use
658
``TestCase.applyDeprecated`` which in one step checks that the API gives
659
the expected deprecation message, and also returns the real result from
660
the method, so that tests can keep running.
662
Coding Style Guidelines
663
=======================
668
``hasattr`` should not be used because it swallows exceptions including
669
``KeyboardInterrupt``. Instead, say something like ::
671
if getattr(thing, 'name', None) is None
677
Please write PEP-8__ compliant code.
679
__ http://www.python.org/peps/pep-0008.html
681
One often-missed requirement is that the first line of docstrings
682
should be a self-contained one-sentence summary.
684
We use 4 space indents for blocks, and never use tab characters. (In vim,
687
Lines should be no more than 79 characters if at all possible.
688
Lines that continue a long statement may be indented in either of
691
within the parenthesis or other character that opens the block, e.g.::
697
or indented by four spaces::
703
The first is considered clearer by some people; however it can be a bit
704
harder to maintain (e.g. when the method name changes), and it does not
705
work well if the relevant parenthesis is already far to the right. Avoid
708
self.legbone.kneebone.shinbone.toebone.shake_it(one,
714
self.legbone.kneebone.shinbone.toebone.shake_it(one,
720
self.legbone.kneebone.shinbone.toebone.shake_it(
723
For long lists, we like to add a trailing comma and put the closing
724
character on the following line. This makes it easier to add new items in
727
from bzrlib.goo import (
733
There should be spaces between function paramaters, but not between the
734
keyword name and the value::
736
call(1, 3, cheese=quark)
740
;(defface my-invalid-face
741
; '((t (:background "Red" :underline t)))
742
; "Face used to highlight invalid constructs or other uglyties"
745
(defun my-python-mode-hook ()
746
;; setup preferred indentation style.
747
(setq fill-column 79)
748
(setq indent-tabs-mode nil) ; no tabs, never, I will not repeat
749
; (font-lock-add-keywords 'python-mode
750
; '(("^\\s *\t" . 'my-invalid-face) ; Leading tabs
751
; ("[ \t]+$" . 'my-invalid-face) ; Trailing spaces
752
; ("^[ \t]+$" . 'my-invalid-face)); Spaces only
756
(add-hook 'python-mode-hook 'my-python-mode-hook)
758
The lines beginning with ';' are comments. They can be activated
759
if one want to have a strong notice of some tab/space usage
766
* Imports should be done at the top-level of the file, unless there is
767
a strong reason to have them lazily loaded when a particular
768
function runs. Import statements have a cost, so try to make sure
769
they don't run inside hot functions.
771
* Module names should always be given fully-qualified,
772
i.e. ``bzrlib.hashcache`` not just ``hashcache``.
778
Functions, methods or members that are "private" to bzrlib are given
779
a leading underscore prefix. Names without a leading underscore are
780
public not just across modules but to programmers using bzrlib as an
781
API. As a consequence, a leading underscore is appropriate for names
782
exposed across modules but that are not to be exposed to bzrlib API
785
We prefer class names to be concatenated capital words (``TestCase``)
786
and variables, methods and functions to be lowercase words joined by
787
underscores (``revision_id``, ``get_revision``).
789
For the purposes of naming some names are treated as single compound
790
words: "filename", "revno".
792
Consider naming classes as nouns and functions/methods as verbs.
794
Try to avoid using abbreviations in names, because there can be
795
inconsistency if other people use the full name.
801
``revision_id`` not ``rev_id`` or ``revid``
803
Functions that transform one thing to another should be named ``x_to_y``
804
(not ``x2y`` as occurs in some old code.)
810
Python destructors (``__del__``) work differently to those of other
811
languages. In particular, bear in mind that destructors may be called
812
immediately when the object apparently becomes unreferenced, or at some
813
later time, or possibly never at all. Therefore we have restrictions on
814
what can be done inside them.
816
0. Never use a __del__ method without asking Martin/Robert first.
818
1. Never rely on a ``__del__`` method running. If there is code that
819
must run, do it from a ``finally`` block instead.
821
2. Never ``import`` from inside a ``__del__`` method, or you may crash the
824
3. In some places we raise a warning from the destructor if the object
825
has not been cleaned up or closed. This is considered OK: the warning
826
may not catch every case but it's still useful sometimes.
832
In some places we have variables which point to callables that construct
833
new instances. That is to say, they can be used a lot like class objects,
834
but they shouldn't be *named* like classes:
836
> I think that things named FooBar should create instances of FooBar when
837
> called. Its plain confusing for them to do otherwise. When we have
838
> something that is going to be used as a class - that is, checked for via
839
> isinstance or other such idioms, them I would call it foo_class, so that
840
> it is clear that a callable is not sufficient. If it is only used as a
841
> factory, then yes, foo_factory is what I would use.
847
Several places in Bazaar use (or will use) a registry, which is a
848
mapping from names to objects or classes. The registry allows for
849
loading in registered code only when it's needed, and keeping
850
associated information such as a help string or description.
856
To make startup time faster, we use the ``bzrlib.lazy_import`` module to
857
delay importing modules until they are actually used. ``lazy_import`` uses
858
the same syntax as regular python imports. So to import a few modules in a
861
from bzrlib.lazy_import import lazy_import
862
lazy_import(globals(), """
871
revision as _mod_revision,
873
import bzrlib.transport
877
At this point, all of these exist as a ``ImportReplacer`` object, ready to
878
be imported once a member is accessed. Also, when importing a module into
879
the local namespace, which is likely to clash with variable names, it is
880
recommended to prefix it as ``_mod_<module>``. This makes it clearer that
881
the variable is a module, and these object should be hidden anyway, since
882
they shouldn't be imported into other namespaces.
885
Modules versus Members
886
~~~~~~~~~~~~~~~~~~~~~~
888
While it is possible for ``lazy_import()`` to import members of a module
889
when using the ``from module import member`` syntax, it is recommended to
890
only use that syntax to load sub modules ``from module import submodule``.
891
This is because variables and classes can frequently be used without
892
needing a sub-member for example::
894
lazy_import(globals(), """
895
from module import MyClass
899
return isinstance(x, MyClass)
901
This will incorrectly fail, because ``MyClass`` is a ``ImportReplacer``
902
object, rather than the real class.
905
Passing to Other Variables
906
~~~~~~~~~~~~~~~~~~~~~~~~~~
908
It also is incorrect to assign ``ImportReplacer`` objects to other variables.
909
Because the replacer only knows about the original name, it is unable to
910
replace other variables. The ``ImportReplacer`` class will raise an
911
``IllegalUseOfScopeReplacer`` exception if it can figure out that this
912
happened. But it requires accessing a member more than once from the new
913
variable, so some bugs are not detected right away.
919
The null revision is the ancestor of all revisions. Its revno is 0, its
920
revision-id is ``null:``, and its tree is the empty tree. When referring
921
to the null revision, please use ``bzrlib.revision.NULL_REVISION``. Old
922
code sometimes uses ``None`` for the null revision, but this practice is
929
Processing Command Lines
930
------------------------
932
bzrlib has a standard framework for parsing command lines and calling
933
processing routines associated with various commands. See builtins.py
934
for numerous examples.
937
Standard Parameter Types
938
------------------------
940
There are some common requirements in the library: some parameters need to be
941
unicode safe, some need byte strings, and so on. At the moment we have
942
only codified one specific pattern: Parameters that need to be unicode
943
should be checked via ``bzrlib.osutils.safe_unicode``. This will coerce the
944
input into unicode in a consistent fashion, allowing trivial strings to be
945
used for programmer convenience, but not performing unpredictably in the
946
presence of different locales.
952
(The strategy described here is what we want to get to, but it's not
953
consistently followed in the code at the moment.)
955
bzrlib is intended to be a generically reusable library. It shouldn't
956
write messages to stdout or stderr, because some programs that use it
957
might want to display that information through a GUI or some other
960
We can distinguish two types of output from the library:
962
1. Structured data representing the progress or result of an
963
operation. For example, for a commit command this will be a list
964
of the modified files and the finally committed revision number
967
These should be exposed either through the return code or by calls
968
to a callback parameter.
970
A special case of this is progress indicators for long-lived
971
operations, where the caller should pass a ProgressBar object.
973
2. Unstructured log/debug messages, mostly for the benefit of the
974
developers or users trying to debug problems. This should always
975
be sent through ``bzrlib.trace`` and Python ``logging``, so that
976
it can be redirected by the client.
978
The distinction between the two is a bit subjective, but in general if
979
there is any chance that a library would want to see something as
980
structured data, we should make it so.
982
The policy about how output is presented in the text-mode client
983
should be only in the command-line tool.
990
Bazaar has online help for various topics through ``bzr help COMMAND`` or
991
equivalently ``bzr command -h``. We also have help on command options,
992
and on other help topics. (See ``help_topics.py``.)
994
As for python docstrings, the first paragraph should be a single-sentence
995
synopsis of the command.
997
The help for options should be one or more proper sentences, starting with
998
a capital letter and finishing with a full stop (period).
1000
All help messages and documentation should have two spaces between
1007
In general tests should be placed in a file named test_FOO.py where
1008
FOO is the logical thing under test. That file should be placed in the
1009
tests subdirectory under the package being tested.
1011
For example, tests for merge3 in bzrlib belong in bzrlib/tests/test_merge3.py.
1012
See bzrlib/tests/test_sampler.py for a template test script.
1014
Tests can be written for the UI or for individual areas of the library.
1015
Choose whichever is appropriate: if adding a new command, or a new command
1016
option, then you should be writing a UI test. If you are both adding UI
1017
functionality and library functionality, you will want to write tests for
1018
both the UI and the core behaviours. We call UI tests 'blackbox' tests
1019
and they are found in ``bzrlib/tests/blackbox/*.py``.
1021
When writing blackbox tests please honour the following conventions:
1023
1. Place the tests for the command 'name' in
1024
bzrlib/tests/blackbox/test_name.py. This makes it easy for developers
1025
to locate the test script for a faulty command.
1027
2. Use the 'self.run_bzr("name")' utility function to invoke the command
1028
rather than running bzr in a subprocess or invoking the
1029
cmd_object.run() method directly. This is a lot faster than
1030
subprocesses and generates the same logging output as running it in a
1031
subprocess (which invoking the method directly does not).
1033
3. Only test the one command in a single test script. Use the bzrlib
1034
library when setting up tests and when evaluating the side-effects of
1035
the command. We do this so that the library api has continual pressure
1036
on it to be as functional as the command line in a simple manner, and
1037
to isolate knock-on effects throughout the blackbox test suite when a
1038
command changes its name or signature. Ideally only the tests for a
1039
given command are affected when a given command is changed.
1041
4. If you have a test which does actually require running bzr in a
1042
subprocess you can use ``run_bzr_subprocess``. By default the spawned
1043
process will not load plugins unless ``--allow-plugins`` is supplied.
1049
We have a rich collection of tools to support writing tests. Please use
1050
them in preference to ad-hoc solutions as they provide portability and
1051
performance benefits.
1056
The ``TreeBuilder`` interface allows the construction of arbitrary trees
1057
with a declarative interface. A sample session might look like::
1059
tree = self.make_branch_and_tree('path')
1060
builder = TreeBuilder()
1061
builder.start_tree(tree)
1062
builder.build(['foo', "bar/", "bar/file"])
1063
tree.commit('commit the tree')
1064
builder.finish_tree()
1066
Please see bzrlib.treebuilder for more details.
1071
The ``BranchBuilder`` interface allows the creation of test branches in a
1072
quick and easy manner. A sample session::
1074
builder = BranchBuilder(self.get_transport().clone('relpath'))
1075
builder.build_commit()
1076
builder.build_commit()
1077
builder.build_commit()
1078
branch = builder.get_branch()
1080
Please see bzrlib.branchbuilder for more details.
1085
We make selective use of doctests__. In general they should provide
1086
*examples* within the API documentation which can incidentally be tested. We
1087
don't try to test every important case using doctests -- regular Python
1088
tests are generally a better solution.
1090
Most of these are in ``bzrlib/doc/api``. More additions are welcome.
1092
__ http://docs.python.org/lib/module-doctest.html
1097
Currently, bzr selftest is used to invoke tests.
1098
You can provide a pattern argument to run a subset. For example,
1099
to run just the blackbox tests, run::
1101
./bzr selftest -v blackbox
1103
To skip a particular test (or set of tests), use the --exclude option
1104
(shorthand -x) like so::
1106
./bzr selftest -v -x blackbox
1108
To list tests without running them, use the --list-only option like so::
1110
./bzr selftest --list-only
1112
This option can be combined with other selftest options (like -x) and
1113
filter patterns to understand their effect.
1116
Handling Errors and Exceptions
1117
==============================
1119
Commands should return non-zero when they encounter circumstances that
1120
the user should really pay attention to - which includes trivial shell
1123
Recommended values are:
1126
1. Conflicts in merge-like operations, or changes are present in
1127
diff-like operations.
1128
2. Unrepresentable diff changes (i.e. binary files that we cannot show
1130
3. An error or exception has occurred.
1131
4. An internal error occurred (one that shows a traceback.)
1133
Errors are handled through Python exceptions. Exceptions should be defined
1134
inside bzrlib.errors, so that we can see the whole tree at a glance.
1136
We broadly classify errors as either being either internal or not,
1137
depending on whether ``internal_error`` is set or not. If we think it's our
1138
fault, we show a backtrace, an invitation to report the bug, and possibly
1139
other details. This is the default for errors that aren't specifically
1140
recognized as being caused by a user error. Otherwise we show a briefer
1141
message, unless -Derror was given.
1143
Many errors originate as "environmental errors" which are raised by Python
1144
or builtin libraries -- for example IOError. These are treated as being
1145
our fault, unless they're caught in a particular tight scope where we know
1146
that they indicate a user errors. For example if the repository format
1147
is not found, the user probably gave the wrong path or URL. But if one of
1148
the files inside the repository is not found, then it's our fault --
1149
either there's a bug in bzr, or something complicated has gone wrong in
1150
the environment that means one internal file was deleted.
1152
Many errors are defined in ``bzrlib/errors.py`` but it's OK for new errors
1153
to be added near the place where they are used.
1155
Exceptions are formatted for the user by conversion to a string
1156
(eventually calling their ``__str__`` method.) As a convenience the
1157
``._fmt`` member can be used as a template which will be mapped to the
1158
error's instance dict.
1160
New exception classes should be defined when callers might want to catch
1161
that exception specifically, or when it needs a substantially different
1164
Exception strings should start with a capital letter and should not have a
1165
final fullstop. If long, they may contain newlines to break the text.
1171
When you change bzrlib, please update the relevant documentation for the
1172
change you made: Changes to commands should update their help, and
1173
possibly end user tutorials; changes to the core library should be
1174
reflected in API documentation.
1179
If you make a user-visible change, please add a note to the NEWS file.
1180
The description should be written to make sense to someone who's just
1181
a user of bzr, not a developer: new functions or classes shouldn't be
1182
mentioned, but new commands, changes in behaviour or fixed nontrivial
1183
bugs should be listed. See the existing entries for an idea of what
1186
Within each release, entries in the news file should have the most
1187
user-visible changes first. So the order should be approximately:
1189
* changes to existing behaviour - the highest priority because the
1190
user's existing knowledge is incorrect
1191
* new features - should be brought to their attention
1192
* bug fixes - may be of interest if the bug was affecting them, and
1193
should include the bug number if any
1194
* major documentation changes
1195
* changes to internal interfaces
1197
People who made significant contributions to each change are listed in
1198
parenthesis. This can include reporting bugs (particularly with good
1199
details or reproduction recipes), submitting patches, etc.
1204
The docstring of a command is used by ``bzr help`` to generate help output
1205
for the command. The list 'takes_options' attribute on a command is used by
1206
``bzr help`` to document the options for the command - the command
1207
docstring does not need to document them. Finally, the '_see_also'
1208
attribute on a command can be used to reference other related help topics.
1213
Functions, methods, classes and modules should have docstrings
1214
describing how they are used.
1216
The first line of the docstring should be a self-contained sentence.
1218
For the special case of Command classes, this acts as the user-visible
1219
documentation shown by the help command.
1221
The docstrings should be formatted as reStructuredText_ (like this
1222
document), suitable for processing using the epydoc_ tool into HTML
1225
.. _reStructuredText: http://docutils.sourceforge.net/rst.html
1226
.. _epydoc: http://epydoc.sourceforge.net/
1235
The copyright policy for bzr was recently made clear in this email (edited
1236
for grammatical correctness)::
1238
The attached patch cleans up the copyright and license statements in
1239
the bzr source. It also adds tests to help us remember to add them
1240
with the correct text.
1242
We had the problem that lots of our files were "Copyright Canonical
1243
Development Ltd" which is not a real company, and some other variations
1244
on this theme. Also, some files were missing the GPL statements.
1246
I want to be clear about the intent of this patch, since copyright can
1247
be a little controversial.
1249
1) The big motivation for this is not to shut out the community, but
1250
just to clean up all of the invalid copyright statements.
1252
2) It has been the general policy for bzr that we want a single
1253
copyright holder for all of the core code. This is following the model
1254
set by the FSF, which makes it easier to update the code to a new
1255
license in case problems are encountered. (For example, if we want to
1256
upgrade the project universally to GPL v3 it is much simpler if there is
1257
a single copyright holder). It also makes it clearer if copyright is
1258
ever debated, there is a single holder, which makes it easier to defend
1259
in court, etc. (I think the FSF position is that if you assign them
1260
copyright, they can defend it in court rather than you needing to, and
1261
I'm sure Canonical would do the same).
1262
As such, Canonical has requested copyright assignments from all of the
1265
3) If someone wants to add code and not attribute it to Canonical, there
1266
is a specific list of files that are excluded from this check. And the
1267
test failure indicates where that is, and how to update it.
1269
4) If anyone feels that I changed a copyright statement incorrectly, just
1270
let me know, and I'll be happy to correct it. Whenever you have large
1271
mechanical changes like this, it is possible to make some mistakes.
1273
Just to reiterate, this is a community project, and it is meant to stay
1274
that way. Core bzr code is copyright Canonical for legal reasons, and
1275
the tests are just there to help us maintain that.
1278
Miscellaneous Topics
1279
####################
1284
Bazaar has a few facilities to help debug problems by going into pdb_, the
1287
.. _pdb: http://docs.python.org/lib/debugger-commands.html
1289
If the ``BZR_PDB`` environment variable is set
1290
then bzr will go into pdb post-mortem mode when an unhandled exception
1293
If you send a SIGQUIT signal to bzr, which can be done by pressing
1294
Ctrl-\\ on Unix, bzr will go into the debugger immediately. You can
1295
continue execution by typing ``c``. This can be disabled if necessary
1296
by setting the environment variable ``BZR_SIGQUIT_PDB=0``.
1303
Integer identifier for a revision on the main line of a branch.
1304
Revision 0 is always the null revision; others are 1-based
1305
indexes into the branch's revision history.
1308
Unicode and Encoding Support
1309
============================
1311
This section discusses various techniques that Bazaar uses to handle
1312
characters that are outside the ASCII set.
1317
When a ``Command`` object is created, it is given a member variable
1318
accessible by ``self.outf``. This is a file-like object, which is bound to
1319
``sys.stdout``, and should be used to write information to the screen,
1320
rather than directly writing to ``sys.stdout`` or calling ``print``.
1321
This file has the ability to translate Unicode objects into the correct
1322
representation, based on the console encoding. Also, the class attribute
1323
``encoding_type`` will effect how unprintable characters will be
1324
handled. This parameter can take one of 3 values:
1327
Unprintable characters will be represented with a suitable replacement
1328
marker (typically '?'), and no exception will be raised. This is for
1329
any command which generates text for the user to review, rather than
1330
for automated processing.
1331
For example: ``bzr log`` should not fail if one of the entries has text
1332
that cannot be displayed.
1335
Attempting to print an unprintable character will cause a UnicodeError.
1336
This is for commands that are intended more as scripting support, rather
1337
than plain user review.
1338
For exampl: ``bzr ls`` is designed to be used with shell scripting. One
1339
use would be ``bzr ls --null --unknows | xargs -0 rm``. If ``bzr``
1340
printed a filename with a '?', the wrong file could be deleted. (At the
1341
very least, the correct file would not be deleted). An error is used to
1342
indicate that the requested action could not be performed.
1345
Do not attempt to automatically convert Unicode strings. This is used
1346
for commands that must handle conversion themselves.
1347
For example: ``bzr diff`` needs to translate Unicode paths, but should
1348
not change the exact text of the contents of the files.
1351
``bzrlib.urlutils.unescape_for_display``
1352
----------------------------------------
1354
Because Transports work in URLs (as defined earlier), printing the raw URL
1355
to the user is usually less than optimal. Characters outside the standard
1356
set are printed as escapes, rather than the real character, and local
1357
paths would be printed as ``file://`` urls. The function
1358
``unescape_for_display`` attempts to unescape a URL, such that anything
1359
that cannot be printed in the current encoding stays an escaped URL, but
1360
valid characters are generated where possible.
1366
The ``bzrlib.osutils`` module has many useful helper functions, including
1367
some more portable variants of functions in the standard library.
1369
In particular, don't use ``shutil.rmtree`` unless it's acceptable for it
1370
to fail on Windows if some files are readonly or still open elsewhere.
1371
Use ``bzrlib.osutils.rmtree`` instead.
1377
We write some extensions in C using pyrex. We design these to work in
1380
* User with no C compiler
1381
* User with C compiler
1384
The recommended way to install bzr is to have a C compiler so that the
1385
extensions can be built, but if no C compiler is present, the pure python
1386
versions we supply will work, though more slowly.
1388
For developers we recommend that pyrex be installed, so that the C
1389
extensions can be changed if needed.
1391
For the C extensions, the extension module should always match the
1392
original python one in all respects (modulo speed). This should be
1393
maintained over time.
1395
To create an extension, add rules to setup.py for building it with pyrex,
1396
and with distutils. Now start with an empty .pyx file. At the top add
1397
"include 'yourmodule.py'". This will import the contents of foo.py into this
1398
file at build time - remember that only one module will be loaded at
1399
runtime. Now you can subclass classes, or replace functions, and only your
1400
changes need to be present in the .pyx file.
1402
Note that pyrex does not support all 2.4 programming idioms, so some
1403
syntax changes may be required. I.e.
1405
- 'from foo import (bar, gam)' needs to change to not use the brackets.
1406
- 'import foo.bar as bar' needs to be 'import foo.bar; bar = foo.bar'
1408
If the changes are too dramatic, consider
1409
maintaining the python code twice - once in the .pyx, and once in the .py,
1410
and no longer including the .py file.
1413
Making Installers for OS Windows
1414
================================
1415
To build a win32 installer, see the instructions on the wiki page:
1416
http://bazaar-vcs.org/BzrWin32Installer
1419
Core Developer Tasks
1420
####################
1425
What is a Core Developer?
1426
-------------------------
1428
While everyone in the Bazaar community is welcome and encouraged to
1429
propose and submit changes, a smaller team is reponsible for pulling those
1430
changes together into a cohesive whole. In addition to the general developer
1431
stuff covered above, "core" developers have responsibility for:
1434
* reviewing blueprints
1436
* managing releases.
1439
Removing barriers to community participation is a key reason for adopting
1440
distributed VCS technology. While DVCS removes many technical barriers,
1441
a small number of social barriers are often necessary instead.
1442
By documenting how the above things are done, we hope to
1443
encourage more people to participate in these activities, keeping the
1444
differences between core and non-core contributors to a minimum.
1447
The Development Lifecycle
1448
-------------------------
1450
As a rule, Bazaar development follows a 4 week cycle:
1452
* 2 weeks - general changes
1453
* 1 week - feature freeze
1454
* 1 week+ - Release Candidate stabilization
1456
During the FeatureFreeze week, the trunk (bzr.dev) is open in a limited
1457
way: only low risk changes, critical and high priority fixes are accepted
1458
during this time. At the end of FeatureFreeze, a branch is created for the
1459
first Release Candidate and the trunk is reopened for general development
1460
on the *next* release. A week or so later, the final release is packaged
1461
assuming no serious problems were encountered with the one or more Release
1465
There is a one week overlap between the start of one release and
1466
the end of the previous one.
1469
Communicating and Coordinating
1470
------------------------------
1472
While it has many advantages, one of the challenges of distributed
1473
development is keeping everyone else aware of what you're working on.
1474
There are numerous ways to do this:
1476
#. Assign bugs to yourself in Launchpad
1477
#. Mention it on the mailing list
1478
#. Mention it on IRC
1480
As well as the email notifcations that occur when merge requests are sent
1481
and reviewed, you can keep others informed of where you're spending your
1482
energy by emailing the **bazaar-commits** list implicitly. To do this,
1483
install and configure the Email plugin. One way to do this is add these
1484
configuration settings to your central configuration file (e.g.
1485
``~/.bazaar/bazaar.conf`` on Linux)::
1488
email = Joe Smith <joe.smith@internode.on.net>
1489
smtp_server = mail.internode.on.net:25
1491
Then add these lines for the relevant branches in ``locations.conf``::
1493
post_commit_to = bazaar-commits@lists.canonical.com
1494
post_commit_mailer = smtplib
1496
While attending a sprint, RobertCollins' Dbus plugin is useful for the
1497
same reason. See the documentation within the plugin for information on
1498
how to set it up and configure it.
1504
Setting Up Your Workspace for Reviews
1505
-------------------------------------
1507
TODO: Incorporate John Arbash Meinel's detailed email to Ian C on the
1508
numerous ways of setting up integration branches.
1511
The Review Checklist
1512
--------------------
1514
See `A Closer Look at the Merge & Review Process`_
1515
for information on the gates used to decide whether code can be merged
1516
or not and details on how review results are recorded and communicated.
1519
The Importance of Timely Reviews
1520
--------------------------------
1522
Good reviews do take time. They also regularly require a solid
1523
understanding of the overall code base. In practice, this means a small
1524
number of people often have a large review burden - with knowledge comes
1525
responsibility. No one like their merge requests sitting in a queue going
1526
nowhere, so reviewing sooner rather than later is strongly encouraged.
1535
Of the many workflows supported by Bazaar, the one adopted for Bazaar
1536
development itself is known as "Decentralized with automatic gatekeeper".
1537
To repeat the explanation of this given on
1538
http://bazaar-vcs.org/Workflows:
1541
In this workflow, each developer has their own branch or
1542
branches, plus read-only access to the mainline. A software gatekeeper
1543
(e.g. PQM) has commit rights to the main branch. When a developer wants
1544
their work merged, they request the gatekeeper to merge it. The gatekeeper
1545
does a merge, a compile, and runs the test suite. If the code passes, it
1546
is merged into the mainline.
1548
In a nutshell, here's the overall submission process:
1550
#. get your work ready (including review except for trivial changes)
1551
#. push to a public location
1552
#. ask PQM to merge from that location
1555
At present, PQM always takes the changes to merge from a branch
1556
at a URL that can be read by it. For Bazaar, that means a public,
1557
typically http, URL.
1559
As a result, the following things are needed to use PQM for submissions:
1561
#. A publicly available web server
1562
#. Your OpenPGP key registered with PQM (contact RobertCollins for this)
1563
#. The PQM plugin installed and configured (not strictly required but
1564
highly recommended).
1567
Selecting a Public Branch Location
1568
----------------------------------
1570
If you don't have your own web server running, branches can always be
1571
pushed to Launchpad. Here's the process for doing that:
1573
Depending on your location throughout the world and the size of your
1574
repository though, it is often quicker to use an alternative public
1575
location to Launchpad, particularly if you can set up your own repo and
1576
push into that. By using an existing repo, push only needs to send the
1577
changes, instead of the complete repository every time. Note that it is
1578
easy to register branches in other locations with Launchpad so no benefits
1579
are lost by going this way.
1582
For Canonical staff, http://people.ubuntu.com/~<user>/ is one
1583
suggestion for public http branches. Contact your manager for information
1584
on accessing this system if required.
1586
It should also be noted that best practice in this area is subject to
1587
change as things evolve. For example, once the Bazaar smart server on
1588
Launchpad supports server-side branching, the performance situation will
1589
be very different to what it is now (Jun 2007).
1592
Configuring the PQM Plug-In
1593
---------------------------
1595
While not strictly required, the PQM plugin automates a few things and
1596
reduces the chance of error. Before looking at the plugin, it helps to
1597
understand a little more how PQM operates. Basically, PQM requires an
1598
email indicating what you want it to do. The email typically looks like
1601
star-merge source-branch target-branch
1605
star-merge http://bzr.arbash-meinel.com/branches/bzr/jam-integration http://bazaar-vcs.org/bzr/bzr.dev
1607
Note that the command needs to be on one line. The subject of the email
1608
will be used for the commit message. The email also needs to be ``gpg``
1609
signed with a key that PQM accepts.
1611
The advantages of using the PQM plugin are:
1613
#. You can use the config policies to make it easy to set up public
1614
branches, so you don't have to ever type the full paths you want to merge
1617
#. It checks to make sure the public branch last revision matches the
1618
local last revision so you are submitting what you think you are.
1620
#. It uses the same public_branch and smtp sending settings as bzr-email,
1621
so if you have one set up, you have the other mostly set up.
1623
#. Thunderbird refuses to not wrap lines, and request lines are usually
1624
pretty long (you have 2 long URLs in there).
1626
Here are sample configuration settings for the PQM plugin. Here are the
1627
lines in bazaar.conf::
1630
email = Joe Smith <joe.smith@internode.on.net>
1631
smtp_server=mail.internode.on.net:25
1633
And here are the lines in ``locations.conf`` (or ``branch.conf`` for
1634
dirstate-tags branches)::
1636
[/home/joe/bzr/my-integration]
1637
push_location = sftp://joe-smith@bazaar.launchpad.net/%7Ejoe-smith/bzr/my-integration/
1638
push_location:policy = norecurse
1639
public_branch = http://bazaar.launchpad.net/~joe-smith/bzr/my-integration/
1640
public_branch:policy = appendpath
1641
pqm_email = Bazaar PQM <pqm@bazaar-vcs.org>
1642
pqm_branch = http://bazaar-vcs.org/bzr/bzr.dev
1644
Note that the push settings will be added by the first ``push`` on
1645
a branch. Indeed the preferred way to generate the lines above is to use
1646
``push`` with an argument, then copy-and-paste the other lines into
1653
Here is one possible recipe once the above environment is set up:
1655
#. pull bzr.dev => my-integration
1656
#. merge patch => my-integration
1657
#. fix up any final merge conflicts (NEWS being the big killer here).
1663
The ``push`` step is not required if ``my-integration`` is a checkout of
1666
Because of defaults, you can type a single message into commit and
1667
pqm-commit will reuse that.
1670
Tracking Change Acceptance
1671
--------------------------
1673
The web interface to PQM is https://pqm.bazaar-vcs.org/. After submitting
1674
a change, you can visit this URL to confirm it was received and placed in
1677
When PQM completes processing a change, an email is sent to you with the
1681
Reviewing Blueprints
1682
====================
1684
Blueprint Tracking Using Launchpad
1685
----------------------------------
1687
New features typically require a fair amount of discussion, design and
1688
debate. For Bazaar, that information is often captured in a so-called
1689
"blueprint" on our Wiki. Overall tracking of blueprints and their status
1690
is done using Launchpad's relevant tracker,
1691
https://blueprints.launchpad.net/bzr/. Once a blueprint for ready for
1692
review, please announce it on the mailing list.
1694
Alternatively, send an email begining with [RFC] with the proposal to the
1695
list. In some cases, you may wish to attach proposed code or a proposed
1696
developer document if that best communicates the idea. Debate can then
1697
proceed using the normal merge review processes.
1700
Recording Blueprint Review Feedback
1701
-----------------------------------
1703
Unlike its Bug Tracker, Launchpad's Blueprint Tracker doesn't currently
1704
(Jun 2007) support a chronological list of comment responses. Review
1705
feedback can either be recorded on the Wiki hosting the blueprints or by
1706
using Launchpad's whiteboard feature.
1715
As the two senior developers, Martin Pool and Robert Collins coordinate
1716
the overall Bazaar product development roadmap. Core developers provide
1717
input and review into this, particularly during sprints. It's totally
1718
expected that community members ought to be working on things that
1719
interest them the most. The roadmap is valuable though because it provides
1720
context for understanding where the product is going as a whole and why.
1723
Using Releases and Milestones in Launchpad
1724
------------------------------------------
1726
TODO ... (Exact policies still under discussion)
1732
Keeping on top of bugs reported is an important part of ongoing release
1733
planning. Everyone in the community is welcome and encouraged to raise
1734
bugs, confirm bugs raised by others, and nominate a priority. Practically
1735
though, a good percentage of bug triage is often done by the core
1736
developers, partially because of their depth of product knowledge.
1738
With respect to bug triage, core developers are encouraged to play an
1739
active role with particular attention to the following tasks:
1741
* keeping the number of unconfirmed bugs low
1742
* ensuring the priorities are generally right (everything as critical - or
1743
medium - is meaningless)
1744
* looking out for regressions and turning those around sooner rather than later.
1747
As well as prioritizing bugs and nominating them against a
1748
target milestone, Launchpad lets core developers offer to mentor others in
1758
To start a new release cycle:
1760
#. Send mail to the list with the key dates, who will be the release
1761
manager, and the main themes or targetted bugs. Ask people to nominate
1762
objectives, or point out an high-risk things that are best done early,
1763
or that interact with other changes.
1765
#. Add a new "series" in Launchpad at <https://launchpad.net/bzr/+addseries>. There is one
1766
series for every *x.y* release.
1768
Weekly Status Updates
1769
---------------------
1771
TODO: Things to cover:
1773
* Early communication to downstream teams (e.g. Launchpad) about changes in dependencies.
1774
* Reminder re lifecycle and where we're up to right now
1775
* Summary of recent successes and pending work
1776
* Reminder re release objectives
1777
* Reminder re things needing attention, e.g. bug triage, reviews, testing of certain things, etc.
1783
TODO: Get material from http://bazaar-vcs.org/FeatureFreeze.
1787
Making a Release or Release Candidate
1788
-------------------------------------
1790
.. Was previously at http://bazaar-vcs.org/ReleaseChecklist
1792
.. TODO: Still needs more clarity on what's in a RC versus a final
1795
.. TODO: Too much of this is manual but could be automated...
1797
This is the procedure for making a new bzr release:
1799
#. If the release is the first candidate, make a new branch in PQM. (Contact RobertCollins for this step).
1801
Register the branch at https://launchpad.net/products/bzr/+addbranch
1803
#. Run the automatic test suite and any non-automated tests. (For example, try a download over http; these should eventually be scripted though not automatically run.). Try to have all optional dependencies installed so that there are no tests skipped. Also make sure that you have the c extensions compiled (``make`` or ``python setup.py build_ext -i``).
1805
#. In the release branch, update ``version_info`` in ``./bzrlib/__init__.py``
1807
#. Add the date and release number to ``./NEWS``.
1809
#. Update the release number in the README. (It's not there as of 0.15, but please check).
1811
#. Commit these changes to the release branch, using a command like::
1813
bzr commit -m "(jam) Release 0.12rc1."
1815
The diff before you commit will be something like::
1817
=== modified file 'NEWS'
1818
--- NEWS 2006-10-23 13:11:17 +0000
1819
+++ NEWS 2006-10-23 22:50:50 +0000
1822
+bzr 0.12rc1 2006-10-23
1827
=== modified file 'bzrlib/__init__.py'
1828
--- bzrlib/__init__.py 2006-10-16 01:47:43 +0000
1829
+++ bzrlib/__init__.py 2006-10-23 22:49:46 +0000
1831
# Python version 2.0 is (2, 0, 0, 'final', 0)." Additionally we use a
1832
# releaselevel of 'dev' for unreleased under-development code.
1834
-version_info = (0, 12, 0, 'dev', 0)
1835
+version_info = (0, 12, 0, 'candidate', 1)
1837
if version_info[3] == 'final':
1838
version_string = '%d.%d.%d' % version_info[:3]
1840
#. Send the changes to PQM, to update the official master branch.
1842
#. When PQM succeeds, pull down the master release branch.
1844
#. Merge the release branch back into the trunk. Check that changes in NEWS were merged into the right sections. If it's not already done, advance the version number in bzr and bzrlib/__init__.py Submit this back into pqm for bzr.dev.
1846
#. Make a distribution directory by running e.g. ``bzr export /tmp/bzr-<version>/`` in the working directory.
1848
#. Run make in /tmp/bzr-<version>. This creates the extensions from the pyrex source.
1850
#. Run the test suite in the distribution directory
1852
#. Run ``setup.py install`` --root=prefix to do a test install into your system directory, home directory, or some other prefix. Check the install worked and that the installed version is usable. (run the bzr script from the installed path with PYTHONPATH set to the site-packages directory it created). i.e. ::
1854
python setup.py install --root=installed
1855
PYTHONPATH=installed/usr/lib/python2.4/site-packages installed/usr/bin/bzr
1857
#. Clean the tree to get rid of .pyc files etc: make clean && rm -rf build && rm bzrlib/_*.c bzrlib/_*.so
1859
#. Generate the reference documentation in text format: make doc/en/user-reference/bzr_man.txt.
1861
#. Change back to your original branch and then run: make clean && make to create the compiled pyrex extensions. You then need to copy the .c files over to the exported directory.
1863
``find . -name "*.c"`` will tell you which files you need.
1865
#. Create the release tarball::
1867
cd /tmp && tar czf bzr-<version>.tar.gz bzr-<version>
1869
#. Sign the tarball with e.g. ``gpg --detach-sign -a bzr-0.10rc1.tar.gz``
1872
Publishing the release
1873
----------------------
1875
Now you have the releasable product. The next step is making it
1876
available to the world.
1878
#. In <https://launchpad.net/bzr/> click the "Release series" for this
1879
series, to take you to e.g. <https://launchpad.net/bzr/1.1>. Then
1880
click "Register a release", and add information about this release.
1882
#. Within that release, upload the source tarball and the GPG signature.
1884
(These used to also be uploaded to
1885
<sftp://escudero.ubuntu.com/srv/bazaar.canonical.com/www/releases/src>
1886
but that's not accessible to all developers, and gets some mime types
1889
#. Link from http://bazaar-vcs.org/Download to the tarball and signature.
1891
#. Update http://doc.bazaar-vcs.org/ to have a directory of documentation
1892
for this release. (Controlled by the ``update-bzr-docs`` script on
1893
escudero, and also update the ``latest`` symlink in
1894
``/srv/bazaar.canonical.com/doc/``.)
1896
#. Announce on the `Bazaar home page`__
1898
__ http://bazaar-vcs.org/
1901
Announcing the release
1902
----------------------
1904
Now that the release is publicly available, tell people about it.
1906
#. Announce to ``bazaar-announce`` and ``bazaar`` mailing lists.
1907
The announce mail will look something like this:
1909
| Subject: bzr 0.11 release candidate 1
1911
| INTRO HERE. Mention the release number and date, and why the release. (i.e. release candidate for testing, final release of a version, backport/bugfix etc).
1914
| http://bazaar-vcs.org/releases/src/bzr-VERSION.tar.gz
1915
| and GPG signature:
1916
| http://bazaar-vcs.org/releases/src/bzr-VERSION.tar.gz.sig
1918
| DESCRIBE-CHANGES-IN-OVERVIEW-HERE
1920
| DESCRIBE-when the next release will be (if there is another - i.e. this is a release candidate)
1922
| Many thanks to all the contributors to this release! I've included the
1923
| contents of NEWS for VERSION below:
1925
To generate the data from NEWS, just copy and paste the relevant news section and clean it up as appropriate. The main clean-up task is to confirm that all major changes are indeed covered. This can be done by running ``bzr log`` back to the point when the branch was opened and cross checking the changes against the NEWS entries.
1927
(RC announcements should remind plugin maintainers to update their plugins.)
1929
* For point releases (i.e. a release candidate, or an incremental fix to a released version) take everything in the relevant NEWS secion : for 0.11rc2 take everything in NEWS from the bzr 0.11rc2 line to the bzr 0.11rc1 line further down.
1931
* For major releases (i.e. 0.11, 0.12 etc), take all the combined NEWS sections from within that version: for 0.11 take all of the 0.11 specific section, plus 0.11rc2, plus 0.11rc1 etc.
1933
#. Update the `news side menu`__ -- this currently requires downloading the file, editing it, deleting it, and uploading a replacement.
1935
__ http://bazaar-vcs.org/site/menu?action=AttachFile&do=view&target=news.html
1937
#. Update the IRC channel topic. Use the ``/topic`` command to do this, ensuring the new topic text keeps the project name, web site link, etc.
1939
#. Announce on http://freshmeat.net/projects/bzr/
1941
This should be done for both release candidates and final releases. If you do not have a Freshmeat account yet, ask one of the existing admins.
1943
#. Update http://en.wikipedia.org/wiki/Bzr -- this should be done for final releases but not Release Candidates.
1945
#. Package maintainers should update packages when they see the
1950
#. Post to http://mail.python.org/mailman/listinfo/python-announce-list for major releases
1952
#. Update the python package index: <http://pypi.python.org/pypi/bzr> - best
1955
python setup.py register
1957
Remember to check the results afterwards.
1960
Making Win32 installers
1961
-----------------------
1963
**XXX:** This information is now probably obsolete, as Alexander uploads
1964
direct to Launchpad. --mbp 20080116
1966
Alexander Belchenko has been very good about getting packaged installers compiled (see Win32ReleaseChecklist for details). He generally e-mails John Arbash Meinel when they are ready. This is just a brief checklist of what needs to be done.
1968
#. Download and verify the sha1 sums and gpg signatures. Frequently the sha1 files are in dos mode, and need to be converted to unix mode (strip off the trailing ``\r``) before they veryify correctly.
1970
#. Upload to the Launchpad page for this release.
1972
#. Upload to escudero (to the b.c.c/www/releases/win32 directory) using sftp, lftp or rsync
1974
#. Cat the contents of the .sha1 files into the SHA1SUM.
1976
#. Update the SHA1SUM and MD5SUM files using something like ``md5sum bzr-0.14.0.win32.exe >> MD5SUM``. Make sure you use append (>>) rather than overwrite (>).
1978
#. Verify once again that everything is correct with ``sha1sum -c SHA1SUM`` and ``md5sum -c MD5SUM``.
1980
#. Update ``.htaccess`` so that the 'bzr-latest.win32.exe' links point to the latest release. This is not done for candidate releases, only for final releases. (example: bzr-0.14.0, but not bzr-0.14.0rc1).
1982
#. Make sure these urls work as expected:
1984
http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.5.exe
1986
http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.5.exe.asc
1988
http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.4.exe
1990
http://bazaar-vcs.org/releases/win32/bzr-latest.win32-py2.4.exe.asc
1992
http://bazaar-vcs.org/releases/win32/bzr-setup-latest.exe
1994
http://bazaar-vcs.org/releases/win32/bzr-setup-latest.exe.asc
1996
They should all try to download a file with the correct version number.
1998
#. Update http://bazaar-vcs.org/Download to indicate the newly available versions.
2000
#. Update http://bazaar-vcs.org/WindowsDownloads to have the correct version number as well as the correct sha1sum displayed.
2004
vim: ft=rst tw=74 ai
added
removed
doc/developers/HACKING.txt
