1
============================
2
Guidelines for modifying bzr
3
============================
7
(The current version of this document is available in the file ``HACKING``
8
in the source tree, or at http://doc.bazaar-vcs.org/current/hacking.html)
13
* New functionality should have test cases. Preferably write the
14
test before writing the code.
16
In general, you can test at either the command-line level or the
17
internal API level. See Writing Tests below for more detail.
19
* Try to practice Test-Driven Development. before fixing a bug, write a
20
test case so that it does not regress. Similarly for adding a new
21
feature: write a test case for a small version of the new feature before
22
starting on the code itself. Check the test fails on the old code, then
23
add the feature or fix and check it passes.
25
* Exceptions should be defined inside bzrlib.errors, so that we can
26
see the whole tree at a glance.
5
This document describes the Bazaar internals and the development process.
6
It's meant for people interested in developing Bazaar, and some parts will
7
also be useful to people developing Bazaar plugins.
9
If you have any questions or something seems to be incorrect, unclear or
10
missing, please talk to us in ``irc://irc.freenode.net/#bzr``, or write to
11
the Bazaar mailing list. To propose a correction or addition to this
12
document, send a merge request or new text to the mailing list.
14
The latest developer documentation can be found online at
15
http://doc.bazaar-vcs.org/developers/.
21
Exploring the Bazaar Platform
22
=============================
24
Before making changes, it's a good idea to explore the work already
25
done by others. Perhaps the new feature or improvement you're looking
26
for is available in another plug-in already? If you find a bug,
27
perhaps someone else has already fixed it?
29
To answer these questions and more, take a moment to explore the
30
overall Bazaar Platform. Here are some links to browse:
32
* The Plugins page on the Wiki - http://bazaar-vcs.org/BzrPlugins
34
* The Bazaar product family on Launchpad - https://launchpad.net/bazaar
36
* Bug Tracker for the core product - https://bugs.launchpad.net/bzr/
38
* Blueprint Tracker for the core product - https://blueprints.launchpad.net/bzr/
40
If nothing else, perhaps you'll find inspiration in how other developers
41
have solved their challenges.
43
Finding Something To Do
44
=======================
46
Ad-hoc performance work can also be done. One useful tool is the 'evil' debug
47
flag. For instance running ``bzr -Devil commit -m "test"`` will log a backtrace
48
to the bzr log file for every method call which triggers a slow or non-scalable
49
part of the bzr library. So checking that a given command with ``-Devil`` has
50
no backtraces logged to the log file is a good way to find problem function
51
calls that might be nested deep in the code base.
53
Planning and Discussing Changes
54
===============================
56
There is a very active community around Bazaar. Mostly we meet on IRC
57
(#bzr on irc.freenode.net) and on the mailing list. To join the Bazaar
58
community, see http://bazaar-vcs.org/BzrSupport.
60
If you are planning to make a change, it's a very good idea to mention it
61
on the IRC channel and/or on the mailing list. There are many advantages
62
to involving the community before you spend much time on a change.
65
* you get to build on the wisdom on others, saving time
67
* if others can direct you to similar code, it minimises the work to be done
69
* it assists everyone in coordinating direction, priorities and effort.
71
In summary, maximising the input from others typically minimises the
72
total effort required to get your changes merged. The community is
73
friendly, helpful and always keen to welcome newcomers.
76
Bazaar Development in a Nutshell
77
================================
79
.. was from bazaar-vcs.org/BzrGivingBack
81
One of the fun things about working on a version control system like Bazaar is
82
that the users have a high level of proficiency in contributing back into
83
the tool. Consider the following very brief introduction to contributing back
84
to Bazaar. More detailed instructions are in the following sections.
89
First, get a local copy of the development mainline (See `Why make a local
95
$ bzr branch http://bazaar-vcs.org/bzr/bzr.dev/ bzr.dev
97
Now make your own branch::
99
$ bzr branch bzr.dev 123456-my-bugfix
101
This will give you a branch called "123456-my-bugfix" that you can work on
102
and commit in. Here, you can study the code, make a fix or a new feature.
103
Feel free to commit early and often (after all, it's your branch!).
105
Documentation improvements are an easy place to get started giving back to the
106
Bazaar project. The documentation is in the `doc/` subdirectory of the Bazaar
109
When you are done, make sure that you commit your last set of changes as well!
110
Once you are happy with your changes, ask for them to be merged, as described
113
Making a Merge Proposal
114
-----------------------
116
The Bazaar developers use Launchpad to further enable a truly distributed
117
style of development. Anyone can propose a branch for merging into the Bazaar
118
trunk. To start this process, you need to push your branch to Launchpad. To
119
do this, you will need a Launchpad account and user name, e.g.
120
`your_lp_username`. You can push your branch to Launchpad directly from
123
$ bzr push lp:~your_lp_username/bzr/giveback
125
After you have pushed your branch, you will need to propose it for merging to
126
the Bazaar trunk. Go to <https://launchpad.net/your_lp_username/bzr/giveback>
127
and choose "Propose for merging into another branch". Select "~bzr/bzr/trunk"
128
to hand your changes off to the Bazaar developers for review and merging.
130
Why make a local copy of bzr.dev?
131
---------------------------------
133
Making a local mirror of bzr.dev is not strictly necessary, but it means
135
- You can use that copy of bzr.dev as your main bzr executable, and keep it
136
up-to-date using ``bzr pull``.
137
- Certain operations are faster, and can be done when offline. For example:
140
- ``bzr diff -r ancestor:...``
143
- When it's time to create your next branch, it's more convenient. When you
144
have further contributions to make, you should do them in their own branch::
147
$ bzr branch bzr.dev additional_fixes
148
$ cd additional_fixes # hack, hack, hack
152
Understanding the Development Process
153
=====================================
155
The development team follows many practices including:
157
* a public roadmap and planning process in which anyone can participate
159
* time based milestones everyone can work towards and plan around
161
* extensive code review and feedback to contributors
163
* complete and rigorous test coverage on any code contributed
165
* automated validation that all tests still pass before code is merged
166
into the main code branch.
168
The key tools we use to enable these practices are:
170
* Launchpad - https://launchpad.net/
172
* Bazaar - http://bazaar-vcs.org/
174
* Bundle Buggy - http://bundlebuggy.aaronbentley.com/
176
* Patch Queue Manager - https://launchpad.net/pqm/
178
For further information, see http://bazaar-vcs.org/BzrDevelopment.
183
Preparing a Sandbox for Making Changes to Bazaar
184
================================================
186
Bazaar supports many ways of organising your work. See
187
http://bazaar-vcs.org/SharedRepositoryLayouts for a summary of the
188
popular alternatives.
190
Of course, the best choice for you will depend on numerous factors:
191
the number of changes you may be making, the complexity of the changes, etc.
192
As a starting suggestion though:
194
* create a local copy of the main development branch (bzr.dev) by using
197
bzr branch http://bazaar-vcs.org/bzr/bzr.dev/ bzr.dev
199
* keep your copy of bzr.dev pristine (by not developing in it) and keep
200
it up to date (by using bzr pull)
202
* create a new branch off your local bzr.dev copy for each issue
203
(bug or feature) you are working on.
205
This approach makes it easy to go back and make any required changes
206
after a code review. Resubmitting the change is then simple with no
207
risk of accidentally including edits related to other issues you may
208
be working on. After the changes for an issue are accepted and merged,
209
the associated branch can be deleted or archived as you wish.
212
Navigating the Code Base
213
========================
215
.. Was at <http://bazaar-vcs.org/NewDeveloperIntroduction>
217
Some of the key files in this directory are:
220
The command you run to start Bazaar itself. This script is pretty
221
short and just does some checks then jumps into bzrlib.
224
This file covers a brief introduction to Bazaar and lists some of its
228
Summary of changes in each Bazaar release that can affect users or
232
Installs Bazaar system-wide or to your home directory. To perform
233
development work on Bazaar it is not required to run this file - you
234
can simply run the bzr command from the top level directory of your
235
development copy. Note: That if you run setup.py this will create a
236
'build' directory in your development branch. There's nothing wrong
237
with this but don't be confused by it. The build process puts a copy
238
of the main code base into this build directory, along with some other
239
files. You don't need to go in here for anything discussed in this
243
Possibly the most exciting folder of all, bzrlib holds the main code
244
base. This is where you will go to edit python files and contribute to
248
Holds documentation on a whole range of things on Bazaar from the
249
origination of ideas within the project to information on Bazaar
250
features and use cases. Within this directory there is a subdirectory
251
for each translation into a human language. All the documentation
252
is in the ReStructuredText markup language.
255
Documentation specifically targeted at Bazaar and plugin developers.
256
(Including this document.)
260
Automatically-generated API reference information is available at
261
<http://starship.python.net/crew/mwh/bzrlibapi/>.
263
See also the `Bazaar Architectural Overview
264
<http://doc.bazaar-vcs.org/developers/overview.html>`_.
267
The Code Review Process
268
#######################
270
All code changes coming in to Bazaar are reviewed by someone else.
271
Normally changes by core contributors are reviewed by one other core
272
developer, and changes from other people are reviewed by two core
273
developers. Use intelligent discretion if the patch is trivial.
275
Good reviews do take time. They also regularly require a solid
276
understanding of the overall code base. In practice, this means a small
277
number of people often have a large review burden - with knowledge comes
278
responsibility. No one likes their merge requests sitting in a queue going
279
nowhere, so reviewing sooner rather than later is strongly encouraged.
288
Please put a "cover letter" on your merge request explaining:
290
* the reason **why** you're making this change
292
* **how** this change achieves this purpose
294
* anything else you may have fixed in passing
296
* anything significant that you thought of doing, such as a more
297
extensive fix or a different approach, but didn't or couldn't do now
299
A good cover letter makes reviewers' lives easier because they can decide
300
from the letter whether they agree with the purpose and approach, and then
301
assess whether the patch actually does what the cover letter says.
302
Explaining any "drive-by fixes" or roads not taken may also avoid queries
303
from the reviewer. All in all this should give faster and better reviews.
304
Sometimes writing the cover letter helps the submitter realize something
305
else they need to do. The size of the cover letter should be proportional
306
to the size and complexity of the patch.
309
Reviewing proposed changes
310
==========================
312
Anyone is welcome to review code, and reply to the thread with their
315
The simplest way to review a proposed change is to just read the patch on
316
the list or in Bundle Buggy. For more complex changes it may be useful
317
to make a new working tree or branch from trunk, and merge the proposed
318
change into it, so you can experiment with the code or look at a wider
321
There are three main requirements for code to get in:
323
* Doesn't reduce test coverage: if it adds new methods or commands,
324
there should be tests for them. There is a good test framework
325
and plenty of examples to crib from, but if you are having trouble
326
working out how to test something feel free to post a draft patch
329
* Doesn't reduce design clarity, such as by entangling objects
330
we're trying to separate. This is mostly something the more
331
experienced reviewers need to help check.
333
* Improves bugs, features, speed, or code simplicity.
335
Code that goes in should not degrade any of these aspects. Patches are
336
welcome that only cleanup the code without changing the external
337
behaviour. The core developers take care to keep the code quality high
338
and understandable while recognising that perfect is sometimes the enemy
341
It is easy for reviews to make people notice other things which should be
342
fixed but those things should not hold up the original fix being accepted.
343
New things can easily be recorded in the Bug Tracker instead.
345
It's normally much easier to review several smaller patches than one large
346
one. You might want to use ``bzr-loom`` to maintain threads of related
347
work, or submit a preparatory patch that will make your "real" change
351
Checklist for reviewers
352
=======================
354
* Do you understand what the code's doing and why?
356
* Will it perform reasonably for large inputs, both in memory size and
357
run time? Are there some scenarios where performance should be
360
* Is it tested, and are the tests at the right level? Are there both
361
blackbox (command-line level) and API-oriented tests?
363
* If this change will be visible to end users or API users, is it
364
appropriately documented in NEWS?
366
* Does it meet the coding standards below?
368
* If it changes the user-visible behaviour, does it update the help
369
strings and user documentation?
371
* If it adds a new major concept or standard practice, does it update the
372
developer documentation?
374
* (your ideas here...)
380
From May 2009 on, we prefer people to propose code reviews through
383
* <https://launchpad.net/+tour/code-review>
385
* <https://help.launchpad.net/Code/Review>
387
Anyone can propose or comment on a merge proposal just by creating a
390
There are two ways to create a new merge proposal: through the web
391
interface or by email.
394
Proposing a merge through the web
395
---------------------------------
397
To create the proposal through the web, first push your branch to Launchpad.
398
For example, a branch dealing with documentation belonging to the Launchpad
399
User mbp could be pushed as ::
401
bzr push lp:~mbp/bzr/doc
403
Then go to the branch's web page, which in this case would be
404
<https://code.launchpad.net/~mbp/bzr/doc>. You can simplify this step by just
409
You can then click "Propose for merging into another branch", and enter your
410
cover letter (see above) into the web form. Typically you'll want to merge
411
into ``~bzr/bzr/trunk`` which will be the default; you might also want to
412
nominate merging into a release branch for a bug fix. There is the option to
413
specify a specific reviewer or type of review, and you shouldn't normally
416
Submitting the form takes you to the new page about the merge proposal
417
containing the diff of the changes, comments by interested people, and
418
controls to comment or vote on the change.
420
Proposing a merge by mail
421
-------------------------
423
To propose a merge by mail, send a bundle to ``merge@code.launchpad.net``.
425
You can generate a merge request like this::
427
bzr send -o bug-1234.diff
429
``bzr send`` can also send mail directly if you prefer; see the help.
434
From <https://code.launchpad.net/bzr/+activereviews> you can see all
435
currently active reviews, and choose one to comment on. This page also
436
shows proposals that are now approved and should be merged by someone with
440
Reviews through Bundle Buggy
441
============================
443
The Bundle Buggy tool used up to May 2009 is still available as a review
446
Sending patches for review
447
--------------------------
449
If you'd like to propose a change, please post to the
450
bazaar@lists.canonical.com list with a bundle, patch, or link to a
451
branch. Put ``[PATCH]`` or ``[MERGE]`` in the subject so Bundle Buggy
452
can pick it out, and explain the change in the email message text.
453
Remember to update the NEWS file as part of your change if it makes any
454
changes visible to users or plugin developers. Please include a diff
455
against mainline if you're giving a link to a branch.
457
You can generate a merge request like this::
459
bzr send -o bug-1234.patch
461
A ``.patch`` extension is recommended instead of .bundle as many mail clients
462
will send the latter as a binary file.
464
``bzr send`` can also send mail directly if you prefer; see the help.
466
Please do **NOT** put [PATCH] or [MERGE] in the subject line if you don't
467
want it to be merged. If you want comments from developers rather than
468
to be merged, you can put ``[RFC]`` in the subject line.
470
If this change addresses a bug, please put the bug number in the subject
471
line too, in the form ``[#1]`` so that Bundle Buggy can recognize it.
473
If the change is intended for a particular release mark that in the
474
subject too, e.g. ``[1.6]``.
475
Anyone can "vote" on the mailing list by expressing an opinion. Core
476
developers can also vote using Bundle Buggy. Here are the voting codes and
479
:approve: Reviewer wants this submission merged.
480
:tweak: Reviewer wants this submission merged with small changes. (No
482
:abstain: Reviewer does not intend to vote on this patch.
483
:resubmit: Please make changes and resubmit for review.
484
:reject: Reviewer doesn't want this kind of change merged.
485
:comment: Not really a vote. Reviewer just wants to comment, for now.
487
If a change gets two approvals from core reviewers, and no rejections,
488
then it's OK to come in. Any of the core developers can bring it into the
489
bzr.dev trunk and backport it to maintenance branches if required. The
490
Release Manager will merge the change into the branch for a pending
491
release, if any. As a guideline, core developers usually merge their own
492
changes and volunteer to merge other contributions if they were the second
493
reviewer to agree to a change.
495
To track the progress of proposed changes, use Bundle Buggy. See
496
http://bundlebuggy.aaronbentley.com/help for a link to all the
497
outstanding merge requests together with an explanation of the columns.
498
Bundle Buggy will also mail you a link to track just your change.
500
Coding Style Guidelines
501
#######################
506
``hasattr`` should not be used because it swallows exceptions including
507
``KeyboardInterrupt``. Instead, say something like ::
509
if getattr(thing, 'name', None) is None
515
Please write PEP-8__ compliant code.
517
__ http://www.python.org/peps/pep-0008.html
519
One often-missed requirement is that the first line of docstrings
520
should be a self-contained one-sentence summary.
522
We use 4 space indents for blocks, and never use tab characters. (In vim,
525
Trailing white space should be avoided, but is allowed.
526
You should however not make lots of unrelated white space changes.
528
Unix style newlines (LF) are used.
530
Each file must have a newline at the end of it.
532
Lines should be no more than 79 characters if at all possible.
533
Lines that continue a long statement may be indented in either of
536
within the parenthesis or other character that opens the block, e.g.::
542
or indented by four spaces::
548
The first is considered clearer by some people; however it can be a bit
549
harder to maintain (e.g. when the method name changes), and it does not
550
work well if the relevant parenthesis is already far to the right. Avoid
553
self.legbone.kneebone.shinbone.toebone.shake_it(one,
559
self.legbone.kneebone.shinbone.toebone.shake_it(one,
565
self.legbone.kneebone.shinbone.toebone.shake_it(
568
For long lists, we like to add a trailing comma and put the closing
569
character on the following line. This makes it easier to add new items in
572
from bzrlib.goo import (
578
There should be spaces between function parameters, but not between the
579
keyword name and the value::
581
call(1, 3, cheese=quark)
585
;(defface my-invalid-face
586
; '((t (:background "Red" :underline t)))
587
; "Face used to highlight invalid constructs or other uglyties"
590
(defun my-python-mode-hook ()
591
;; setup preferred indentation style.
592
(setq fill-column 79)
593
(setq indent-tabs-mode nil) ; no tabs, never, I will not repeat
594
; (font-lock-add-keywords 'python-mode
595
; '(("^\\s *\t" . 'my-invalid-face) ; Leading tabs
596
; ("[ \t]+$" . 'my-invalid-face) ; Trailing spaces
597
; ("^[ \t]+$" . 'my-invalid-face)); Spaces only
601
(add-hook 'python-mode-hook 'my-python-mode-hook)
603
The lines beginning with ';' are comments. They can be activated
604
if one want to have a strong notice of some tab/space usage
28
611
* Imports should be done at the top-level of the file, unless there is
29
612
a strong reason to have them lazily loaded when a particular
33
616
* Module names should always be given fully-qualified,
34
617
i.e. ``bzrlib.hashcache`` not just ``hashcache``.
36
* Commands should return non-zero when they encounter circumstances that
37
the user should really pay attention to - which includes trivial shell
40
Recommended values are
42
1. Conflicts in merge-like operations, or changes are present in
44
2. Unrepresentable diff changes (i.e. binary files that we cannot show
46
3. An error or exception has occurred.
51
We have a commitment to 6 months API stability - any supported symbol in a
52
release of bzr MUST NOT be altered in any way that would result in
53
breaking existing code that uses it. That means that method names,
54
parameter ordering, parameter names, variable and attribute names etc must
55
not be changed without leaving a 'deprecated forwarder' behind. This even
56
applies to modules and classes.
58
If you wish to change the behaviour of a supported API in an incompatible
59
way, you need to change its name as well. For instance, if I add a optional keyword
60
parameter to branch.commit - that's fine. On the other hand, if I add a
61
keyword parameter to branch.commit which is a *required* transaction
62
object, I should rename the API - i.e. to 'branch.commit_transaction'.
64
When renaming such supported API's, be sure to leave a deprecated_method (or
65
_function or ...) behind which forwards to the new API. See the
66
bzrlib.symbol_versioning module for decorators that take care of the
67
details for you - such as updating the docstring, and issuing a warning
68
when the old api is used.
70
For unsupported API's, it does not hurt to follow this discipline, but its
71
not required. Minimally though, please try to rename things so that
72
callers will at least get an AttributeError rather than weird results.
75
Standard parameter types
76
------------------------
78
There are some common requirements in the library: some parameters need to be
79
unicode safe, some need byte strings, and so on. At the moment we have
80
only codified one specific pattern: Parameters that need to be unicode
81
should be check via 'bzrlib.osutils.safe_unicode'. This will coerce the
82
input into unicode in a consistent fashion, allowing trivial strings to be
83
used for programmer convenience, but not performing unpredictably in the
84
presence of different locales.
89
If you change the behaviour of a command, please update its docstring
90
in bzrlib/commands.py. This is displayed by the 'bzr help' command.
95
If you make a user-visible change, please add a note to the NEWS file.
96
The description should be written to make sense to someone who's just
97
a user of bzr, not a developer: new functions or classes shouldn't be
98
mentioned, but new commands, changes in behaviour or fixed nontrivial
99
bugs should be listed. See the existing entries for an idea of what
102
Within each release, entries in the news file should have the most
103
user-visible changes first. So the order should be approximately:
105
* changes to existing behaviour - the highest priority because the
106
user's existing knowledge is incorrect
107
* new features - should be brought to their attention
108
* bug fixes - may be of interest if the bug was affecting them, and
109
should include the bug number if any
110
* major documentation changes
111
* changes to internal interfaces
113
People who made significant contributions to each change are listed in
114
parenthesis. This can include reporting bugs (particularly with good
115
details or reproduction recipes), submitting patches, etc.
120
Functions, methods, classes and modules should have docstrings
121
describing how they are used.
123
The first line of the docstring should be a self-contained sentence.
125
For the special case of Command classes, this acts as the user-visible
126
documentation shown by the help command.
128
The docstrings should be formatted as reStructuredText_ (like this
129
document), suitable for processing using the epydoc_ tool into HTML
132
.. _reStructuredText: http://docutils.sourceforge.net/rst.html
133
.. _epydoc: http://epydoc.sourceforge.net/
140
Please write PEP-8__ compliant code.
142
One often-missed requirement is that the first line of docstrings
143
should be a self-contained one-sentence summary.
145
__ http://www.python.org/peps/pep-0008.html
152
Functions, methods or members that are in some sense "private" are given
153
a leading underscore prefix. This is just a hint that code outside the
154
implementation should probably not use that interface.
623
Functions, methods or members that are "private" to bzrlib are given
624
a leading underscore prefix. Names without a leading underscore are
625
public not just across modules but to programmers using bzrlib as an
626
API. As a consequence, a leading underscore is appropriate for names
627
exposed across modules but that are not to be exposed to bzrlib API
156
630
We prefer class names to be concatenated capital words (``TestCase``)
157
631
and variables, methods and functions to be lowercase words joined by
209
688
> factory, then yes, foo_factory is what I would use.
694
Several places in Bazaar use (or will use) a registry, which is a
695
mapping from names to objects or classes. The registry allows for
696
loading in registered code only when it's needed, and keeping
697
associated information such as a help string or description.
700
InterObject and multiple dispatch
701
=================================
703
The ``InterObject`` provides for two-way `multiple dispatch`__: matching
704
up for example a source and destination repository to find the right way
705
to transfer data between them.
707
.. __: http://en.wikipedia.org/wiki/Multiple_dispatch
709
There is a subclass ``InterObject`` classes for each type of object that is
710
dispatched this way, e.g. ``InterRepository``. Calling ``.get()`` on this
711
class will return an ``InterObject`` instance providing the best match for
712
those parameters, and this instance then has methods for operations
715
inter = InterRepository.get(source_repo, target_repo)
716
inter.fetch(revision_id)
718
``InterRepository`` also acts as a registry-like object for its
719
subclasses, and they can be added through ``.register_optimizer``. The
720
right one to run is selected by asking each class, in reverse order of
721
registration, whether it ``.is_compatible`` with the relevant objects.
726
To make startup time faster, we use the ``bzrlib.lazy_import`` module to
727
delay importing modules until they are actually used. ``lazy_import`` uses
728
the same syntax as regular python imports. So to import a few modules in a
731
from bzrlib.lazy_import import lazy_import
732
lazy_import(globals(), """
741
revision as _mod_revision,
743
import bzrlib.transport
747
At this point, all of these exist as a ``ImportReplacer`` object, ready to
748
be imported once a member is accessed. Also, when importing a module into
749
the local namespace, which is likely to clash with variable names, it is
750
recommended to prefix it as ``_mod_<module>``. This makes it clearer that
751
the variable is a module, and these object should be hidden anyway, since
752
they shouldn't be imported into other namespaces.
754
While it is possible for ``lazy_import()`` to import members of a module
755
when using the ``from module import member`` syntax, it is recommended to
756
only use that syntax to load sub modules ``from module import submodule``.
757
This is because variables and classes can frequently be used without
758
needing a sub-member for example::
760
lazy_import(globals(), """
761
from module import MyClass
765
return isinstance(x, MyClass)
767
This will incorrectly fail, because ``MyClass`` is a ``ImportReplacer``
768
object, rather than the real class.
770
It also is incorrect to assign ``ImportReplacer`` objects to other variables.
771
Because the replacer only knows about the original name, it is unable to
772
replace other variables. The ``ImportReplacer`` class will raise an
773
``IllegalUseOfScopeReplacer`` exception if it can figure out that this
774
happened. But it requires accessing a member more than once from the new
775
variable, so some bugs are not detected right away.
781
The null revision is the ancestor of all revisions. Its revno is 0, its
782
revision-id is ``null:``, and its tree is the empty tree. When referring
783
to the null revision, please use ``bzrlib.revision.NULL_REVISION``. Old
784
code sometimes uses ``None`` for the null revision, but this practice is
788
Object string representations
789
=============================
791
Python prints objects using their ``__repr__`` method when they are
792
written to logs, exception tracebacks, or the debugger. We want
793
objects to have useful representations to help in determining what went
796
If you add a new class you should generally add a ``__repr__`` method
797
unless there is an adequate method in a parent class. There should be a
800
Representations should typically look like Python constructor syntax, but
801
they don't need to include every value in the object and they don't need
802
to be able to actually execute. They're to be read by humans, not
803
machines. Don't hardcode the classname in the format, so that we get the
804
correct value if the method is inherited by a subclass. If you're
805
printing attributes of the object, including strings, you should normally
806
use ``%r`` syntax (to call their repr in turn).
808
Try to avoid the representation becoming more than one or two lines long.
809
(But balance this against including useful information, and simplicity of
812
Because repr methods are often called when something has already gone
813
wrong, they should be written somewhat more defensively than most code.
814
The object may be half-initialized or in some other way in an illegal
815
state. The repr method shouldn't raise an exception, or it may hide the
816
(probably more useful) underlying exception.
821
return '%s(%r)' % (self.__class__.__name__,
828
A bare ``except`` statement will catch all exceptions, including ones that
829
really should terminate the program such as ``MemoryError`` and
830
``KeyboardInterrupt``. They should rarely be used unless the exception is
831
later re-raised. Even then, think about whether catching just
832
``Exception`` (which excludes system errors in Python2.5 and later) would
839
All code should be exercised by the test suite. See the `Bazaar Testing
840
Guide <http://doc.bazaar-vcs.org/developers/testing.html>`_ for detailed
841
information about writing tests.
850
We have a commitment to 6 months API stability - any supported symbol in a
851
release of bzr MUST NOT be altered in any way that would result in
852
breaking existing code that uses it. That means that method names,
853
parameter ordering, parameter names, variable and attribute names etc must
854
not be changed without leaving a 'deprecated forwarder' behind. This even
855
applies to modules and classes.
857
If you wish to change the behaviour of a supported API in an incompatible
858
way, you need to change its name as well. For instance, if I add an optional keyword
859
parameter to branch.commit - that's fine. On the other hand, if I add a
860
keyword parameter to branch.commit which is a *required* transaction
861
object, I should rename the API - i.e. to 'branch.commit_transaction'.
863
When renaming such supported API's, be sure to leave a deprecated_method (or
864
_function or ...) behind which forwards to the new API. See the
865
bzrlib.symbol_versioning module for decorators that take care of the
866
details for you - such as updating the docstring, and issuing a warning
867
when the old API is used.
869
For unsupported API's, it does not hurt to follow this discipline, but it's
870
not required. Minimally though, please try to rename things so that
871
callers will at least get an AttributeError rather than weird results.
874
Deprecation decorators
875
----------------------
877
``bzrlib.symbol_versioning`` provides decorators that can be attached to
878
methods, functions, and other interfaces to indicate that they should no
879
longer be used. For example::
881
@deprecated_method(deprecated_in((0, 1, 4)))
883
return self._new_foo()
885
To deprecate a static method you must call ``deprecated_function``
886
(**not** method), after the staticmethod call::
889
@deprecated_function(deprecated_in((0, 1, 4)))
890
def create_repository(base, shared=False, format=None):
892
When you deprecate an API, you should not just delete its tests, because
893
then we might introduce bugs in them. If the API is still present at all,
894
it should still work. The basic approach is to use
895
``TestCase.applyDeprecated`` which in one step checks that the API gives
896
the expected deprecation message, and also returns the real result from
897
the method, so that tests can keep running.
899
Deprecation warnings will be suppressed for final releases, but not for
900
development versions or release candidates, or when running ``bzr
901
selftest``. This gives developers information about whether their code is
902
using deprecated functions, but avoids confusing users about things they
909
Processing Command Lines
910
------------------------
912
bzrlib has a standard framework for parsing command lines and calling
913
processing routines associated with various commands. See builtins.py
914
for numerous examples.
917
Standard Parameter Types
918
------------------------
920
There are some common requirements in the library: some parameters need to be
921
unicode safe, some need byte strings, and so on. At the moment we have
922
only codified one specific pattern: Parameters that need to be unicode
923
should be checked via ``bzrlib.osutils.safe_unicode``. This will coerce the
924
input into unicode in a consistent fashion, allowing trivial strings to be
925
used for programmer convenience, but not performing unpredictably in the
926
presence of different locales.
215
932
(The strategy described here is what we want to get to, but it's not
246
963
should be only in the command-line tool.
251
In general tests should be placed in a file named test_FOO.py where
252
FOO is the logical thing under test. That file should be placed in the
253
tests subdirectory under the package being tested.
255
For example, tests for merge3 in bzrlib belong in bzrlib/tests/test_merge3.py.
256
See bzrlib/selftest/test_sampler.py for a template test script.
258
Tests can be written for the UI or for individual areas of the library.
259
Choose whichever is appropriate: if adding a new command, or a new command
260
option, then you should be writing a UI test. If you are both adding UI
261
functionality and library functionality, you will want to write tests for
262
both the UI and the core behaviours. We call UI tests 'blackbox' tests
263
and they are found in ``bzrlib/tests/blackbox/*.py``.
265
When writing blackbox tests please honour the following conventions:
267
1. Place the tests for the command 'name' in
268
bzrlib/tests/blackbox/test_name.py. This makes it easy for developers
269
to locate the test script for a faulty command.
271
2. Use the 'self.run_bzr("name")' utility function to invoke the command
272
rather than running bzr in a subprocess or invoking the
273
cmd_object.run() method directly. This is a lot faster than
274
subprocesses and generates the same logging output as running it in a
275
subprocess (which invoking the method directly does not).
277
3. Only test the one command in a single test script. Use the bzrlib
278
library when setting up tests and when evaluating the side-effects of
279
the command. We do this so that the library api has continual pressure
280
on it to be as functional as the command line in a simple manner, and
281
to isolate knock-on effects throughout the blackbox test suite when a
282
command changes it name or signature. Ideally only the tests for a
283
given command are affected when a given command is changed.
966
Progress and Activity Indications
967
---------------------------------
969
bzrlib has a way for code to display to the user that stuff is happening
970
during a long operation. There are two particular types: *activity* which
971
means that IO is happening on a Transport, and *progress* which means that
972
higher-level application work is occurring. Both are drawn together by
975
Transport objects are responsible for calling `report_transport_activity`
978
Progress uses a model/view pattern: application code acts on a
979
`ProgressTask` object, which notifies the UI when it needs to be
980
displayed. Progress tasks form a stack. To create a new progress task on
981
top of the stack, call `bzrlib.ui.ui_factory.nested_progress_bar()`, then
982
call `update()` on the returned ProgressTask. It can be updated with just
983
a text description, with a numeric count, or with a numeric count and
984
expected total count. If an expected total count is provided the view
985
can show the progress moving along towards the expected total.
987
The user should call `finish` on the `ProgressTask` when the logical
988
operation has finished, so it can be removed from the stack.
990
Progress tasks have a complex relationship with generators: it's a very
991
good place to use them, but because python2.4 does not allow ``finally``
992
blocks in generators it's hard to clean them up properly. In this case
993
it's probably better to have the code calling the generator allocate a
994
progress task for its use and then call `finalize` when it's done, which
995
will close it if it was not already closed. The generator should also
996
finish the progress task when it exits, because it may otherwise be a long
997
time until the finally block runs.
1003
Bazaar has online help for various topics through ``bzr help COMMAND`` or
1004
equivalently ``bzr command -h``. We also have help on command options,
1005
and on other help topics. (See ``help_topics.py``.)
1007
As for python docstrings, the first paragraph should be a single-sentence
1008
synopsis of the command.
1010
The help for options should be one or more proper sentences, starting with
1011
a capital letter and finishing with a full stop (period).
1013
All help messages and documentation should have two spaces between
1017
Handling Errors and Exceptions
1018
==============================
1020
Commands should return non-zero when they encounter circumstances that
1021
the user should really pay attention to - which includes trivial shell
1024
Recommended values are:
1027
1. Conflicts in merge-like operations, or changes are present in
1028
diff-like operations.
1029
2. Unrepresentable diff changes (i.e. binary files that we cannot show
1031
3. An error or exception has occurred.
1032
4. An internal error occurred (one that shows a traceback.)
1034
Errors are handled through Python exceptions. Exceptions should be defined
1035
inside bzrlib.errors, so that we can see the whole tree at a glance.
1037
We broadly classify errors as either being either internal or not,
1038
depending on whether ``internal_error`` is set or not. If we think it's our
1039
fault, we show a backtrace, an invitation to report the bug, and possibly
1040
other details. This is the default for errors that aren't specifically
1041
recognized as being caused by a user error. Otherwise we show a briefer
1042
message, unless -Derror was given.
1044
Many errors originate as "environmental errors" which are raised by Python
1045
or builtin libraries -- for example IOError. These are treated as being
1046
our fault, unless they're caught in a particular tight scope where we know
1047
that they indicate a user errors. For example if the repository format
1048
is not found, the user probably gave the wrong path or URL. But if one of
1049
the files inside the repository is not found, then it's our fault --
1050
either there's a bug in bzr, or something complicated has gone wrong in
1051
the environment that means one internal file was deleted.
1053
Many errors are defined in ``bzrlib/errors.py`` but it's OK for new errors
1054
to be added near the place where they are used.
1056
Exceptions are formatted for the user by conversion to a string
1057
(eventually calling their ``__str__`` method.) As a convenience the
1058
``._fmt`` member can be used as a template which will be mapped to the
1059
error's instance dict.
1061
New exception classes should be defined when callers might want to catch
1062
that exception specifically, or when it needs a substantially different
1065
#. If it is something that a caller can recover from, a custom exception
1068
#. If it is a data consistency issue, using a builtin like
1069
``ValueError``/``TypeError`` is reasonable.
1071
#. If it is a programmer error (using an api incorrectly)
1072
``AssertionError`` is reasonable.
1074
#. Otherwise, use ``BzrError`` or ``InternalBzrError``.
1076
Exception strings should start with a capital letter and should not have a
1077
final fullstop. If long, they may contain newlines to break the text.
1083
Do not use the Python ``assert`` statement, either in tests or elsewhere.
1084
A source test checks that it is not used. It is ok to explicitly raise
1089
* It makes the behaviour vary depending on whether bzr is run with -O
1090
or not, therefore giving a chance for bugs that occur in one case or
1091
the other, several of which have already occurred: assertions with
1092
side effects, code which can't continue unless the assertion passes,
1093
cases where we should give the user a proper message rather than an
1095
* It's not that much shorter than an explicit if/raise.
1096
* It tends to lead to fuzzy thinking about whether the check is
1097
actually needed or not, and whether it's an internal error or not
1098
* It tends to cause look-before-you-leap patterns.
1099
* It's unsafe if the check is needed to protect the integrity of the
1101
* It tends to give poor messages since the developer can get by with
1102
no explanatory text at all.
1103
* We can't rely on people always running with -O in normal use, so we
1104
can't use it for tests that are actually expensive.
1105
* Expensive checks that help developers are better turned on from the
1106
test suite or a -D flag.
1107
* If used instead of ``self.assert*()`` in tests it makes them falsely pass with -O.
1113
When you change bzrlib, please update the relevant documentation for the
1114
change you made: Changes to commands should update their help, and
1115
possibly end user tutorials; changes to the core library should be
1116
reflected in API documentation.
1121
If you make a user-visible change, please add a note to the NEWS file.
1122
The description should be written to make sense to someone who's just
1123
a user of bzr, not a developer: new functions or classes shouldn't be
1124
mentioned, but new commands, changes in behaviour or fixed nontrivial
1125
bugs should be listed. See the existing entries for an idea of what
1128
Within each release, entries in the news file should have the most
1129
user-visible changes first. So the order should be approximately:
1131
* changes to existing behaviour - the highest priority because the
1132
user's existing knowledge is incorrect
1133
* new features - should be brought to their attention
1134
* bug fixes - may be of interest if the bug was affecting them, and
1135
should include the bug number if any
1136
* major documentation changes
1137
* changes to internal interfaces
1139
People who made significant contributions to each change are listed in
1140
parenthesis. This can include reporting bugs (particularly with good
1141
details or reproduction recipes), submitting patches, etc.
288
We make selective use of doctests__. In general they should provide
289
*examples* within the API documentation which can incidentally be tested. We
290
don't try to test every important case using doctests -- regular Python
291
tests are generally a better solution.
293
Most of these are in ``bzrlib/doc/api``. More additions are welcome.
295
__ http://docs.python.org/lib/module-doctest.html
300
Currently, bzr selftest is used to invoke tests.
301
You can provide a pattern argument to run a subset. For example,
302
to run just the blackbox tests, run::
304
./bzr selftest -v blackbox
306
To skip a particular test (or set of tests), you need to use a negative
309
./bzr selftest '^(?!.*blackbox)'
312
Errors and exceptions
313
=====================
315
Errors are handled through Python exceptions. They can represent user
316
errors, environmental errors or program bugs. Sometimes we can't be sure
317
at the time it's raised which case applies. See bzrlib/errors.py for
318
details on the error-handling practices.
1146
The docstring of a command is used by ``bzr help`` to generate help output
1147
for the command. The list 'takes_options' attribute on a command is used by
1148
``bzr help`` to document the options for the command - the command
1149
docstring does not need to document them. Finally, the '_see_also'
1150
attribute on a command can be used to reference other related help topics.
1155
Functions, methods, classes and modules should have docstrings
1156
describing how they are used.
1158
The first line of the docstring should be a self-contained sentence.
1160
For the special case of Command classes, this acts as the user-visible
1161
documentation shown by the help command.
1163
The docstrings should be formatted as reStructuredText_ (like this
1164
document), suitable for processing using the epydoc_ tool into HTML
1167
.. _reStructuredText: http://docutils.sourceforge.net/rst.html
1168
.. _epydoc: http://epydoc.sourceforge.net/
1177
The copyright policy for bzr was recently made clear in this email (edited
1178
for grammatical correctness)::
1180
The attached patch cleans up the copyright and license statements in
1181
the bzr source. It also adds tests to help us remember to add them
1182
with the correct text.
1184
We had the problem that lots of our files were "Copyright Canonical
1185
Development Ltd" which is not a real company, and some other variations
1186
on this theme. Also, some files were missing the GPL statements.
1188
I want to be clear about the intent of this patch, since copyright can
1189
be a little controversial.
1191
1) The big motivation for this is not to shut out the community, but
1192
just to clean up all of the invalid copyright statements.
1194
2) It has been the general policy for bzr that we want a single
1195
copyright holder for all of the core code. This is following the model
1196
set by the FSF, which makes it easier to update the code to a new
1197
license in case problems are encountered. (For example, if we want to
1198
upgrade the project universally to GPL v3 it is much simpler if there is
1199
a single copyright holder). It also makes it clearer if copyright is
1200
ever debated, there is a single holder, which makes it easier to defend
1201
in court, etc. (I think the FSF position is that if you assign them
1202
copyright, they can defend it in court rather than you needing to, and
1203
I'm sure Canonical would do the same).
1204
As such, Canonical has requested copyright assignments from all of the
1207
3) If someone wants to add code and not attribute it to Canonical, there
1208
is a specific list of files that are excluded from this check. And the
1209
test failure indicates where that is, and how to update it.
1211
4) If anyone feels that I changed a copyright statement incorrectly, just
1212
let me know, and I'll be happy to correct it. Whenever you have large
1213
mechanical changes like this, it is possible to make some mistakes.
1215
Just to reiterate, this is a community project, and it is meant to stay
1216
that way. Core bzr code is copyright Canonical for legal reasons, and
1217
the tests are just there to help us maintain that.
1220
Miscellaneous Topics
1221
####################
1226
Bazaar has a few facilities to help debug problems by going into pdb_, the
1229
.. _pdb: http://docs.python.org/lib/debugger-commands.html
1231
If the ``BZR_PDB`` environment variable is set
1232
then bzr will go into pdb post-mortem mode when an unhandled exception
1235
If you send a SIGQUIT or SIGBREAK signal to bzr then it will drop into the
1236
debugger immediately. SIGQUIT can be generated by pressing Ctrl-\\ on
1237
Unix. SIGBREAK is generated with Ctrl-Pause on Windows (some laptops have
1238
this as Fn-Pause). You can continue execution by typing ``c``. This can
1239
be disabled if necessary by setting the environment variable
1240
``BZR_SIGQUIT_PDB=0``.
1246
Bazaar accepts some global options starting with ``-D`` such as
1247
``-Dhpss``. These set a value in `bzrlib.debug.debug_flags`, and
1248
typically cause more information to be written to the trace file. Most
1249
`mutter` calls should be guarded by a check of those flags so that we
1250
don't write out too much information if it's not needed.
1252
Debug flags may have effects other than just emitting trace messages.
1254
Run ``bzr help global-options`` to see them all.
1256
These flags may also be set as a comma-separated list in the
1257
``debug_flags`` option in e.g. ``~/.bazaar/bazaar.conf``. (Note that it
1258
must be in this global file, not in the branch or location configuration,
1259
because it's currently only loaded at startup time.) For instance you may
1260
want to always record hpss traces and to see full error tracebacks::
1262
debug_flags = hpss, error
432
1326
valid characters are generated where possible.
438
If you'd like to propose a change, please post to the
439
bazaar-ng@lists.canonical.com list with a patch, bzr changeset, or link to a
440
branch. Please put '[patch]' in the subject so we can pick them out, and
441
include some text explaining the change. Remember to put an update to the NEWS
442
file in your diff, if it makes any changes visible to users or plugin
443
developers. Please include a diff against mainline if you're giving a link to
446
Please indicate if you think the code is ready to merge, or if it's just a
447
draft or for discussion. If you want comments from many developers rather than
448
to be merged, you can put '[rfc]' in the subject lines.
450
Anyone is welcome to review code. There are broadly three gates for
453
* Doesn't reduce test coverage: if it adds new methods or commands,
454
there should be tests for them. There is a good test framework
455
and plenty of examples to crib from, but if you are having trouble
456
working out how to test something feel free to post a draft patch
459
* Doesn't reduce design clarity, such as by entangling objects
460
we're trying to separate. This is mostly something the more
461
experienced reviewers need to help check.
463
* Improves bugs, features, speed, or code simplicity.
465
Code that goes in should pass all three.
467
If you read a patch please reply and say so. We can use a numeric scale
468
of -1, -0, +0, +1, meaning respectively "really don't want it in current
469
form", "somewhat uncomfortable", "ok with me", and "please put it in".
470
Anyone can "vote". (It's not really voting, just a terse expression.)
472
If something gets say two +1 votes from core reviewers, and no
473
vetos, then it's OK to come in. Any of the core developers can bring it
474
into their integration branch, which I'll merge regularly. (If you do
475
so, please reply and say so.)
478
Making installers for OS Windows
1332
The ``bzrlib.osutils`` module has many useful helper functions, including
1333
some more portable variants of functions in the standard library.
1335
In particular, don't use ``shutil.rmtree`` unless it's acceptable for it
1336
to fail on Windows if some files are readonly or still open elsewhere.
1337
Use ``bzrlib.osutils.rmtree`` instead.
1343
We write some extensions in C using pyrex. We design these to work in
1346
* User with no C compiler
1347
* User with C compiler
1350
The recommended way to install bzr is to have a C compiler so that the
1351
extensions can be built, but if no C compiler is present, the pure python
1352
versions we supply will work, though more slowly.
1354
For developers we recommend that pyrex be installed, so that the C
1355
extensions can be changed if needed.
1357
For the C extensions, the extension module should always match the
1358
original python one in all respects (modulo speed). This should be
1359
maintained over time.
1361
To create an extension, add rules to setup.py for building it with pyrex,
1362
and with distutils. Now start with an empty .pyx file. At the top add
1363
"include 'yourmodule.py'". This will import the contents of foo.py into this
1364
file at build time - remember that only one module will be loaded at
1365
runtime. Now you can subclass classes, or replace functions, and only your
1366
changes need to be present in the .pyx file.
1368
Note that pyrex does not support all 2.4 programming idioms, so some
1369
syntax changes may be required. I.e.
1371
- 'from foo import (bar, gam)' needs to change to not use the brackets.
1372
- 'import foo.bar as bar' needs to be 'import foo.bar; bar = foo.bar'
1374
If the changes are too dramatic, consider
1375
maintaining the python code twice - once in the .pyx, and once in the .py,
1376
and no longer including the .py file.
1379
Making Installers for OS Windows
479
1380
================================
480
1381
To build a win32 installer, see the instructions on the wiki page:
481
1382
http://bazaar-vcs.org/BzrWin32Installer
484
:: vim: ft=rst tw=74 ai
1385
Core Developer Tasks
1386
####################
1391
What is a Core Developer?
1392
-------------------------
1394
While everyone in the Bazaar community is welcome and encouraged to
1395
propose and submit changes, a smaller team is reponsible for pulling those
1396
changes together into a cohesive whole. In addition to the general developer
1397
stuff covered above, "core" developers have responsibility for:
1400
* reviewing blueprints
1402
* managing releases (see `Releasing Bazaar <http://doc.bazaar-vcs.org/developers/releasing.html>`_)
1405
Removing barriers to community participation is a key reason for adopting
1406
distributed VCS technology. While DVCS removes many technical barriers,
1407
a small number of social barriers are often necessary instead.
1408
By documenting how the above things are done, we hope to
1409
encourage more people to participate in these activities, keeping the
1410
differences between core and non-core contributors to a minimum.
1413
Communicating and Coordinating
1414
------------------------------
1416
While it has many advantages, one of the challenges of distributed
1417
development is keeping everyone else aware of what you're working on.
1418
There are numerous ways to do this:
1420
#. Assign bugs to yourself in Launchpad
1421
#. Mention it on the mailing list
1422
#. Mention it on IRC
1424
As well as the email notifcations that occur when merge requests are sent
1425
and reviewed, you can keep others informed of where you're spending your
1426
energy by emailing the **bazaar-commits** list implicitly. To do this,
1427
install and configure the Email plugin. One way to do this is add these
1428
configuration settings to your central configuration file (e.g.
1429
``~/.bazaar/bazaar.conf`` on Linux)::
1432
email = Joe Smith <joe.smith@internode.on.net>
1433
smtp_server = mail.internode.on.net:25
1435
Then add these lines for the relevant branches in ``locations.conf``::
1437
post_commit_to = bazaar-commits@lists.canonical.com
1438
post_commit_mailer = smtplib
1440
While attending a sprint, RobertCollins' Dbus plugin is useful for the
1441
same reason. See the documentation within the plugin for information on
1442
how to set it up and configure it.
1451
Of the many workflows supported by Bazaar, the one adopted for Bazaar
1452
development itself is known as "Decentralized with automatic gatekeeper".
1453
To repeat the explanation of this given on
1454
http://bazaar-vcs.org/Workflows:
1457
In this workflow, each developer has their own branch or
1458
branches, plus read-only access to the mainline. A software gatekeeper
1459
(e.g. PQM) has commit rights to the main branch. When a developer wants
1460
their work merged, they request the gatekeeper to merge it. The gatekeeper
1461
does a merge, a compile, and runs the test suite. If the code passes, it
1462
is merged into the mainline.
1464
In a nutshell, here's the overall submission process:
1466
#. get your work ready (including review except for trivial changes)
1467
#. push to a public location
1468
#. ask PQM to merge from that location
1471
At present, PQM always takes the changes to merge from a branch
1472
at a URL that can be read by it. For Bazaar, that means a public,
1473
typically http, URL.
1475
As a result, the following things are needed to use PQM for submissions:
1477
#. A publicly available web server
1478
#. Your OpenPGP key registered with PQM (contact RobertCollins for this)
1479
#. The PQM plugin installed and configured (not strictly required but
1480
highly recommended).
1483
Selecting a Public Branch Location
1484
----------------------------------
1486
If you don't have your own web server running, branches can always be
1487
pushed to Launchpad. Here's the process for doing that:
1489
Depending on your location throughout the world and the size of your
1490
repository though, it is often quicker to use an alternative public
1491
location to Launchpad, particularly if you can set up your own repo and
1492
push into that. By using an existing repo, push only needs to send the
1493
changes, instead of the complete repository every time. Note that it is
1494
easy to register branches in other locations with Launchpad so no benefits
1495
are lost by going this way.
1498
For Canonical staff, http://people.ubuntu.com/~<user>/ is one
1499
suggestion for public http branches. Contact your manager for information
1500
on accessing this system if required.
1502
It should also be noted that best practice in this area is subject to
1503
change as things evolve. For example, once the Bazaar smart server on
1504
Launchpad supports server-side branching, the performance situation will
1505
be very different to what it is now (Jun 2007).
1508
Configuring the PQM Plug-In
1509
---------------------------
1511
While not strictly required, the PQM plugin automates a few things and
1512
reduces the chance of error. Before looking at the plugin, it helps to
1513
understand a little more how PQM operates. Basically, PQM requires an
1514
email indicating what you want it to do. The email typically looks like
1517
star-merge source-branch target-branch
1521
star-merge http://bzr.arbash-meinel.com/branches/bzr/jam-integration http://bazaar-vcs.org/bzr/bzr.dev
1523
Note that the command needs to be on one line. The subject of the email
1524
will be used for the commit message. The email also needs to be ``gpg``
1525
signed with a key that PQM accepts.
1527
The advantages of using the PQM plugin are:
1529
#. You can use the config policies to make it easy to set up public
1530
branches, so you don't have to ever type the full paths you want to merge
1533
#. It checks to make sure the public branch last revision matches the
1534
local last revision so you are submitting what you think you are.
1536
#. It uses the same public_branch and smtp sending settings as bzr-email,
1537
so if you have one set up, you have the other mostly set up.
1539
#. Thunderbird refuses to not wrap lines, and request lines are usually
1540
pretty long (you have 2 long URLs in there).
1542
Here are sample configuration settings for the PQM plugin. Here are the
1543
lines in bazaar.conf::
1546
email = Joe Smith <joe.smith@internode.on.net>
1547
smtp_server=mail.internode.on.net:25
1549
And here are the lines in ``locations.conf`` (or ``branch.conf`` for
1550
dirstate-tags branches)::
1552
[/home/joe/bzr/my-integration]
1553
push_location = sftp://joe-smith@bazaar.launchpad.net/%7Ejoe-smith/bzr/my-integration/
1554
push_location:policy = norecurse
1555
public_branch = http://bazaar.launchpad.net/~joe-smith/bzr/my-integration/
1556
public_branch:policy = appendpath
1557
pqm_email = Bazaar PQM <pqm@bazaar-vcs.org>
1558
pqm_branch = http://bazaar-vcs.org/bzr/bzr.dev
1560
Note that the push settings will be added by the first ``push`` on
1561
a branch. Indeed the preferred way to generate the lines above is to use
1562
``push`` with an argument, then copy-and-paste the other lines into
1569
Here is one possible recipe once the above environment is set up:
1571
#. pull bzr.dev => my-integration
1572
#. merge patch => my-integration
1573
#. fix up any final merge conflicts (NEWS being the big killer here).
1579
The ``push`` step is not required if ``my-integration`` is a checkout of
1582
Because of defaults, you can type a single message into commit and
1583
pqm-commit will reuse that.
1586
Tracking Change Acceptance
1587
--------------------------
1589
The web interface to PQM is https://pqm.bazaar-vcs.org/. After submitting
1590
a change, you can visit this URL to confirm it was received and placed in
1593
When PQM completes processing a change, an email is sent to you with the
1597
Reviewing Blueprints
1598
====================
1600
Blueprint Tracking Using Launchpad
1601
----------------------------------
1603
New features typically require a fair amount of discussion, design and
1604
debate. For Bazaar, that information is often captured in a so-called
1605
"blueprint" on our Wiki. Overall tracking of blueprints and their status
1606
is done using Launchpad's relevant tracker,
1607
https://blueprints.launchpad.net/bzr/. Once a blueprint for ready for
1608
review, please announce it on the mailing list.
1610
Alternatively, send an email beginning with [RFC] with the proposal to the
1611
list. In some cases, you may wish to attach proposed code or a proposed
1612
developer document if that best communicates the idea. Debate can then
1613
proceed using the normal merge review processes.
1616
Recording Blueprint Review Feedback
1617
-----------------------------------
1619
Unlike its Bug Tracker, Launchpad's Blueprint Tracker doesn't currently
1620
(Jun 2007) support a chronological list of comment responses. Review
1621
feedback can either be recorded on the Wiki hosting the blueprints or by
1622
using Launchpad's whiteboard feature.
1629
Using Releases and Milestones in Launchpad
1630
------------------------------------------
1632
TODO ... (Exact policies still under discussion)
1638
Keeping on top of bugs reported is an important part of ongoing release
1639
planning. Everyone in the community is welcome and encouraged to raise
1640
bugs, confirm bugs raised by others, and nominate a priority. Practically
1641
though, a good percentage of bug triage is often done by the core
1642
developers, partially because of their depth of product knowledge.
1644
With respect to bug triage, core developers are encouraged to play an
1645
active role with particular attention to the following tasks:
1647
* keeping the number of unconfirmed bugs low
1648
* ensuring the priorities are generally right (everything as critical - or
1649
medium - is meaningless)
1650
* looking out for regressions and turning those around sooner rather than later.
1653
As well as prioritizing bugs and nominating them against a
1654
target milestone, Launchpad lets core developers offer to mentor others in
1659
vim: ft=rst tw=74 ai
added
removed
doc/developers/HACKING.txt
