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.
28
* Imports should be done at the top-level of the file, unless there is
29
a strong reason to have them lazily loaded when a particular
30
function runs. Import statements have a cost, so try to make sure
31
they don't run inside hot functions.
33
* Module names should always be given fully-qualified,
34
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
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.canonical.com/developers/.
20
Exploring the Bazaar Platform
21
=============================
23
Before making changes, it's a good idea to explore the work already
24
done by others. Perhaps the new feature or improvement you're looking
25
for is available in another plug-in already? If you find a bug,
26
perhaps someone else has already fixed it?
28
To answer these questions and more, take a moment to explore the
29
overall Bazaar Platform. Here are some links to browse:
31
* The Plugins page on the Wiki - http://wiki.bazaar.canonical.com/BzrPlugins
33
* The Bazaar product family on Launchpad - https://launchpad.net/bazaar
35
* Bug Tracker for the core product - https://bugs.launchpad.net/bzr/
37
If nothing else, perhaps you'll find inspiration in how other developers
38
have solved their challenges.
40
Finding Something To Do
41
=======================
43
Ad-hoc performance work can also be done. One useful tool is the 'evil' debug
44
flag. For instance running ``bzr -Devil commit -m "test"`` will log a backtrace
45
to the bzr log file for every method call which triggers a slow or non-scalable
46
part of the bzr library. So checking that a given command with ``-Devil`` has
47
no backtraces logged to the log file is a good way to find problem function
48
calls that might be nested deep in the code base.
50
Planning and Discussing Changes
51
===============================
53
There is a very active community around Bazaar. Mostly we meet on IRC
54
(#bzr on irc.freenode.net) and on the mailing list. To join the Bazaar
55
community, see http://wiki.bazaar.canonical.com/BzrSupport.
57
If you are planning to make a change, it's a very good idea to mention it
58
on the IRC channel and/or on the mailing list. There are many advantages
59
to involving the community before you spend much time on a change.
62
* you get to build on the wisdom of others, saving time
64
* if others can direct you to similar code, it minimises the work to be done
66
* it assists everyone in coordinating direction, priorities and effort.
68
In summary, maximising the input from others typically minimises the
69
total effort required to get your changes merged. The community is
70
friendly, helpful and always keen to welcome newcomers.
73
Bazaar Development in a Nutshell
74
================================
76
.. was from http://wiki.bazaar.canonical.com/BzrGivingBack
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One of the fun things about working on a version control system like Bazaar is
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that the users have a high level of proficiency in contributing back into
80
the tool. Consider the following very brief introduction to contributing back
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to Bazaar. More detailed instructions are in the following sections.
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First, get a local copy of the development mainline (See `Why make a local
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$ bzr branch lp:bzr bzr.dev
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Now make your own branch::
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$ bzr branch bzr.dev 123456-my-bugfix
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This will give you a branch called "123456-my-bugfix" that you can work on
99
and commit in. Here, you can study the code, make a fix or a new feature.
100
Feel free to commit early and often (after all, it's your branch!).
102
Documentation improvements are an easy place to get started giving back to the
103
Bazaar project. The documentation is in the `doc/` subdirectory of the Bazaar
106
When you are done, make sure that you commit your last set of changes as well!
107
Once you are happy with your changes, ask for them to be merged, as described
110
Making a Merge Proposal
111
-----------------------
113
The Bazaar developers use Launchpad to further enable a truly distributed
114
style of development. Anyone can propose a branch for merging into the Bazaar
115
trunk. To start this process, you need to push your branch to Launchpad. To
116
do this, you will need a Launchpad account and user name, e.g.
117
`your_lp_username`. You can push your branch to Launchpad directly from
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$ bzr push lp:~your_lp_username/bzr/meaningful_name_here
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After you have pushed your branch, you will need to propose it for merging to
123
the Bazaar trunk. Go to
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<https://launchpad.net/your_lp_username/bzr/meaningful_name_here> and choose
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"Propose for merging into another branch". Select "~bzr/bzr/trunk" to hand
126
your changes off to the Bazaar developers for review and merging.
128
Alternatively, after pushing you can use the ``lp-propose`` command to
129
create the merge proposal.
131
Using a meaningful name for your branch will help you and the reviewer(s)
132
better track the submission. Use a very succint description of your submission
133
and prefix it with bug number if needed (lp:~mbp/bzr/484558-merge-directory
134
for example). Alternatively, you can suffix with the bug number
135
(lp:~jameinel/bzr/export-file-511987).
141
Please put a "cover letter" on your merge request explaining:
143
* the reason **why** you're making this change
145
* **how** this change achieves this purpose
147
* anything else you may have fixed in passing
149
* anything significant that you thought of doing, such as a more
150
extensive fix or a different approach, but didn't or couldn't do now
152
A good cover letter makes reviewers' lives easier because they can decide
153
from the letter whether they agree with the purpose and approach, and then
154
assess whether the patch actually does what the cover letter says.
155
Explaining any "drive-by fixes" or roads not taken may also avoid queries
156
from the reviewer. All in all this should give faster and better reviews.
157
Sometimes writing the cover letter helps the submitter realize something
158
else they need to do. The size of the cover letter should be proportional
159
to the size and complexity of the patch.
162
Why make a local copy of bzr.dev?
163
---------------------------------
165
Making a local mirror of bzr.dev is not strictly necessary, but it means
167
- You can use that copy of bzr.dev as your main bzr executable, and keep it
168
up-to-date using ``bzr pull``.
169
- Certain operations are faster, and can be done when offline. For example:
172
- ``bzr diff -r ancestor:...``
175
- When it's time to create your next branch, it's more convenient. When you
176
have further contributions to make, you should do them in their own branch::
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$ bzr branch bzr.dev additional_fixes
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$ cd additional_fixes # hack, hack, hack
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Understanding the Development Process
185
=====================================
187
The development team follows many practices including:
189
* a public roadmap and planning process in which anyone can participate
191
* time based milestones everyone can work towards and plan around
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* extensive code review and feedback to contributors
195
* complete and rigorous test coverage on any code contributed
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* automated validation that all tests still pass before code is merged
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into the main code branch.
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The key tools we use to enable these practices are:
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* Launchpad - https://launchpad.net/
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* Bazaar - http://bazaar.canonical.com/
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* Patch Queue Manager - https://launchpad.net/pqm/
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For further information, see <http://wiki.bazaar.canonical.com/BzrDevelopment>.
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Preparing a Sandbox for Making Changes to Bazaar
214
================================================
216
Bazaar supports many ways of organising your work. See
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http://wiki.bazaar.canonical.com/SharedRepositoryLayouts for a summary of the
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popular alternatives.
220
Of course, the best choice for you will depend on numerous factors:
221
the number of changes you may be making, the complexity of the changes, etc.
222
As a starting suggestion though:
224
* create a local copy of the main development branch (bzr.dev) by using
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bzr branch lp:bzr bzr.dev
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* keep your copy of bzr.dev pristine (by not developing in it) and keep
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it up to date (by using bzr pull)
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* create a new branch off your local bzr.dev copy for each issue
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(bug or feature) you are working on.
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This approach makes it easy to go back and make any required changes
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after a code review. Resubmitting the change is then simple with no
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risk of accidentally including edits related to other issues you may
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be working on. After the changes for an issue are accepted and merged,
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the associated branch can be deleted or archived as you wish.
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Navigating the Code Base
243
========================
245
.. Was at <http://wiki.bazaar.canonical.com/NewDeveloperIntroduction>
247
Some of the key files in this directory are:
250
The command you run to start Bazaar itself. This script is pretty
251
short and just does some checks then jumps into bzrlib.
254
This file covers a brief introduction to Bazaar and lists some of its
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Summary of changes in each Bazaar release that can affect users or
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Installs Bazaar system-wide or to your home directory. To perform
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development work on Bazaar it is not required to run this file - you
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can simply run the bzr command from the top level directory of your
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development copy. Note: That if you run setup.py this will create a
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'build' directory in your development branch. There's nothing wrong
267
with this but don't be confused by it. The build process puts a copy
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of the main code base into this build directory, along with some other
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files. You don't need to go in here for anything discussed in this
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Possibly the most exciting folder of all, bzrlib holds the main code
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base. This is where you will go to edit python files and contribute to
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Holds documentation on a whole range of things on Bazaar from the
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origination of ideas within the project to information on Bazaar
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features and use cases. Within this directory there is a subdirectory
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for each translation into a human language. All the documentation
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is in the ReStructuredText markup language.
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Documentation specifically targeted at Bazaar and plugin developers.
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(Including this document.)
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Automatically-generated API reference information is available at
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<http://starship.python.net/crew/mwh/bzrlibapi/>.
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See also the `Bazaar Architectural Overview
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<http://doc.bazaar.canonical.com/developers/overview.html>`_.
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We don't change APIs in stable branches: any supported symbol in a stable
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release of bzr must not be altered in any way that would result in
53
305
breaking existing code that uses it. That means that method names,
54
306
parameter ordering, parameter names, variable and attribute names etc must
55
307
not be changed without leaving a 'deprecated forwarder' behind. This even
59
311
way, you need to change its name as well. For instance, if I add an optional keyword
60
312
parameter to branch.commit - that's fine. On the other hand, if I add a
61
313
keyword parameter to branch.commit which is a *required* transaction
62
object, I should rename the API - i.e. to 'branch.commit_transaction'.
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object, I should rename the API - i.e. to 'branch.commit_transaction'.
316
(Actually, that may break code that provides a new implementation of
317
``commit`` and doesn't expect to receive the parameter.)
64
319
When renaming such supported API's, be sure to leave a deprecated_method (or
65
320
_function or ...) behind which forwards to the new API. See the
66
321
bzrlib.symbol_versioning module for decorators that take care of the
67
322
details for you - such as updating the docstring, and issuing a warning
68
when the old api is used.
323
when the old API is used.
70
325
For unsupported API's, it does not hurt to follow this discipline, but it's
71
326
not required. Minimally though, please try to rename things so that
72
327
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 checked 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.
330
Deprecation decorators
331
----------------------
333
``bzrlib.symbol_versioning`` provides decorators that can be attached to
334
methods, functions, and other interfaces to indicate that they should no
335
longer be used. For example::
337
@deprecated_method(deprecated_in((0, 1, 4)))
339
return self._new_foo()
341
To deprecate a static method you must call ``deprecated_function``
342
(**not** method), after the staticmethod call::
345
@deprecated_function(deprecated_in((0, 1, 4)))
346
def create_repository(base, shared=False, format=None):
348
When you deprecate an API, you should not just delete its tests, because
349
then we might introduce bugs in them. If the API is still present at all,
350
it should still work. The basic approach is to use
351
``TestCase.applyDeprecated`` which in one step checks that the API gives
352
the expected deprecation message, and also returns the real result from
353
the method, so that tests can keep running.
355
Deprecation warnings will be suppressed for final releases, but not for
356
development versions or release candidates, or when running ``bzr
357
selftest``. This gives developers information about whether their code is
358
using deprecated functions, but avoids confusing users about things they
116
394
I'm sure Canonical would do the same).
117
395
As such, Canonical has requested copyright assignments from all of the
118
396
major contributers.
120
398
3) If someone wants to add code and not attribute it to Canonical, there
121
399
is a specific list of files that are excluded from this check. And the
122
400
test failure indicates where that is, and how to update it.
124
402
4) If anyone feels that I changed a copyright statement incorrectly, just
125
403
let me know, and I'll be happy to correct it. Whenever you have large
126
404
mechanical changes like this, it is possible to make some mistakes.
128
406
Just to reiterate, this is a community project, and it is meant to stay
129
407
that way. Core bzr code is copyright Canonical for legal reasons, and
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408
the tests are just there to help us maintain that.
136
If you change the behaviour of a command, please update its docstring
137
in bzrlib/commands.py. This is displayed by the 'bzr help' command.
142
If you make a user-visible change, please add a note to the NEWS file.
143
The description should be written to make sense to someone who's just
144
a user of bzr, not a developer: new functions or classes shouldn't be
145
mentioned, but new commands, changes in behaviour or fixed nontrivial
146
bugs should be listed. See the existing entries for an idea of what
149
Within each release, entries in the news file should have the most
150
user-visible changes first. So the order should be approximately:
152
* changes to existing behaviour - the highest priority because the
153
user's existing knowledge is incorrect
154
* new features - should be brought to their attention
155
* bug fixes - may be of interest if the bug was affecting them, and
156
should include the bug number if any
157
* major documentation changes
158
* changes to internal interfaces
160
People who made significant contributions to each change are listed in
161
parenthesis. This can include reporting bugs (particularly with good
162
details or reproduction recipes), submitting patches, etc.
167
Functions, methods, classes and modules should have docstrings
168
describing how they are used.
170
The first line of the docstring should be a self-contained sentence.
172
For the special case of Command classes, this acts as the user-visible
173
documentation shown by the help command.
175
The docstrings should be formatted as reStructuredText_ (like this
176
document), suitable for processing using the epydoc_ tool into HTML
179
.. _reStructuredText: http://docutils.sourceforge.net/rst.html
180
.. _epydoc: http://epydoc.sourceforge.net/
187
Please write PEP-8__ compliant code.
189
One often-missed requirement is that the first line of docstrings
190
should be a self-contained one-sentence summary.
192
__ http://www.python.org/peps/pep-0008.html
199
Functions, methods or members that are in some sense "private" are given
200
a leading underscore prefix. This is just a hint that code outside the
201
implementation should probably not use that interface.
203
We prefer class names to be concatenated capital words (``TestCase``)
204
and variables, methods and functions to be lowercase words joined by
205
underscores (``revision_id``, ``get_revision``).
207
For the purposes of naming some names are treated as single compound
208
words: "filename", "revno".
210
Consider naming classes as nouns and functions/methods as verbs.
216
``revision_id`` not ``rev_id`` or ``revid``
218
Functions that transform one thing to another should be named ``x_to_y``
219
(not ``x2y`` as occurs in some old code.)
225
Python destructors (``__del__``) work differently to those of other
226
languages. In particular, bear in mind that destructors may be called
227
immediately when the object apparently becomes unreferenced, or at some
228
later time, or possibly never at all. Therefore we have restrictions on
229
what can be done inside them.
231
0. Never use a __del__ method without asking Martin/Robert first.
233
1. Never rely on a ``__del__`` method running. If there is code that
234
must run, do it from a ``finally`` block instead.
236
2. Never ``import`` from inside a ``__del__`` method, or you may crash the
239
3. In some places we raise a warning from the destructor if the object
240
has not been cleaned up or closed. This is considered OK: the warning
241
may not catch every case but it's still useful sometimes.
247
In some places we have variables which point to callables that construct
248
new instances. That is to say, they can be used a lot like class objects,
249
but they shouldn't be *named* like classes:
251
> I think that things named FooBar should create instances of FooBar when
252
> called. Its plain confusing for them to do otherwise. When we have
253
> something that is going to be used as a class - that is, checked for via
254
> isinstance or other such idioms, them I would call it foo_class, so that
255
> it is clear that a callable is not sufficient. If it is only used as a
256
> factory, then yes, foo_factory is what I would use.
262
Several places in Bazaar use (or will use) a registry, which is a
263
mapping from names to objects or classes. The registry allows for
264
loading in registered code only when it's needed, and keeping
265
associated information such as a help string or description.
271
To make startup time faster, we use the ``bzrlib.lazy_import`` module to
272
delay importing modules until they are actually used. ``lazy_import`` uses
273
the same syntax as regular python imports. So to import a few modules in a
276
from bzrlib.lazy_import import lazy_import
277
lazy_import(globals(), """
286
revision as _mod_revision,
288
import bzrlib.transport
292
At this point, all of these exist as a ``ImportReplacer`` object, ready to
293
be imported once a member is accessed. Also, when importing a module into
294
the local namespace, which is likely to clash with variable names, it is
295
recommended to prefix it as ``_mod_<module>``. This makes it clean that
296
the variable is a module, and these object should be hidden anyway, since
297
they shouldn't be imported into other namespaces.
300
Modules versus Members
301
~~~~~~~~~~~~~~~~~~~~~~
303
While it is possible for ``lazy_import()`` to import members of a module
304
when using the ``from module import member`` syntax, it is recommended to
305
only use that syntax to load sub modules ``from module import submodule``.
306
This is because variables and classes can frequently be used without
307
needing a sub-member for example::
309
lazy_import(globals(), """
310
from module import MyClass
314
return isinstance(x, MyClass)
316
This will incorrectly fail, because ``MyClass`` is a ``ImportReplacer``
317
object, rather than the real class.
320
Passing to other variables
321
~~~~~~~~~~~~~~~~~~~~~~~~~~
323
It also is incorrect to assign ``ImportReplacer`` objects to other variables.
324
Because the replacer only knows about the original name, it is unable to
325
replace other variables. The ``ImportReplacer`` class will raise an
326
``IllegalUseOfScopeReplacer`` exception if it can figure out that this
327
happened. But it requires accessing a member more than once from the new
328
variable, so some bugs are not detected right away.
334
(The strategy described here is what we want to get to, but it's not
335
consistently followed in the code at the moment.)
337
bzrlib is intended to be a generically reusable library. It shouldn't
338
write messages to stdout or stderr, because some programs that use it
339
might want to display that information through a GUI or some other
342
We can distinguish two types of output from the library:
344
1. Structured data representing the progress or result of an
345
operation. For example, for a commit command this will be a list
346
of the modified files and the finally committed revision number
349
These should be exposed either through the return code or by calls
350
to a callback parameter.
352
A special case of this is progress indicators for long-lived
353
operations, where the caller should pass a ProgressBar object.
355
2. Unstructured log/debug messages, mostly for the benefit of the
356
developers or users trying to debug problems. This should always
357
be sent through ``bzrlib.trace`` and Python ``logging``, so that
358
it can be redirected by the client.
360
The distinction between the two is a bit subjective, but in general if
361
there is any chance that a library would want to see something as
362
structured data, we should make it so.
364
The policy about how output is presented in the text-mode client
365
should be only in the command-line tool.
371
In general tests should be placed in a file named test_FOO.py where
372
FOO is the logical thing under test. That file should be placed in the
373
tests subdirectory under the package being tested.
375
For example, tests for merge3 in bzrlib belong in bzrlib/tests/test_merge3.py.
376
See bzrlib/selftest/test_sampler.py for a template test script.
378
Tests can be written for the UI or for individual areas of the library.
379
Choose whichever is appropriate: if adding a new command, or a new command
380
option, then you should be writing a UI test. If you are both adding UI
381
functionality and library functionality, you will want to write tests for
382
both the UI and the core behaviours. We call UI tests 'blackbox' tests
383
and they are found in ``bzrlib/tests/blackbox/*.py``.
385
When writing blackbox tests please honour the following conventions:
387
1. Place the tests for the command 'name' in
388
bzrlib/tests/blackbox/test_name.py. This makes it easy for developers
389
to locate the test script for a faulty command.
391
2. Use the 'self.run_bzr("name")' utility function to invoke the command
392
rather than running bzr in a subprocess or invoking the
393
cmd_object.run() method directly. This is a lot faster than
394
subprocesses and generates the same logging output as running it in a
395
subprocess (which invoking the method directly does not).
397
3. Only test the one command in a single test script. Use the bzrlib
398
library when setting up tests and when evaluating the side-effects of
399
the command. We do this so that the library api has continual pressure
400
on it to be as functional as the command line in a simple manner, and
401
to isolate knock-on effects throughout the blackbox test suite when a
402
command changes its name or signature. Ideally only the tests for a
403
given command are affected when a given command is changed.
405
4. If you have a test which does actually require running bzr in a
406
subprocess you can use ``run_bzr_subprocess``. By default the spawned
407
process will not load plugins unless ``--allow-plugins`` is supplied.
413
We make selective use of doctests__. In general they should provide
414
*examples* within the API documentation which can incidentally be tested. We
415
don't try to test every important case using doctests -- regular Python
416
tests are generally a better solution.
418
Most of these are in ``bzrlib/doc/api``. More additions are welcome.
420
__ http://docs.python.org/lib/module-doctest.html
425
Currently, bzr selftest is used to invoke tests.
426
You can provide a pattern argument to run a subset. For example,
427
to run just the blackbox tests, run::
429
./bzr selftest -v blackbox
431
To skip a particular test (or set of tests), you need to use a negative
434
./bzr selftest '^(?!.*blackbox)'
437
Errors and exceptions
438
=====================
440
Errors are handled through Python exceptions.
442
We broadly classify errors as either being either internal or not,
443
depending on whether ``user_error`` is set or not. If we think it's our
444
fault, we show a backtrace, an invitation to report the bug, and possibly
445
other details. This is the default for errors that aren't specifically
446
recognized as being caused by a user error. Otherwise we show a briefer
447
message, unless -Derror was given.
449
Many errors originate as "environmental errors" which are raised by Python
450
or builtin libraries -- for example IOError. These are treated as being
451
our fault, unless they're caught in a particular tight scope where we know
452
that they indicate a user errors. For example if the repository format
453
is not found, the user probably gave the wrong path or URL. But if one of
454
the files inside the repository is not found, then it's our fault --
455
either there's a bug in bzr, or something complicated has gone wrong in
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the environment that means one internal file was deleted.
458
Many errors are defined in ``bzrlib/errors.py`` but it's OK for new errors
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to be added near the place where they are used.
461
Exceptions are formatted for the user by conversion to a string
462
(eventually calling their ``__str__`` method.) As a convenience the
463
``._fmt`` member can be used as a template which will be mapped to the
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error's instance dict.
466
New exception classes should be defined when callers might want to catch
467
that exception specifically, or when it needs a substantially different
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Exception strings should start with a capital letter and should not have a
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final fullstop. If long, they may contain newlines to break the text.
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Bazaar has a few facilities to help debug problems by going into pdb_, the
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.. _pdb: http://docs.python.org/lib/debugger-commands.html
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If the ``BZR_PDB`` environment variable is set
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then bzr will go into pdb post-mortem mode when an unhandled exception
426
If you send a SIGQUIT or SIGBREAK signal to bzr then it will drop into the
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debugger immediately. SIGQUIT can be generated by pressing Ctrl-\\ on
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Unix. SIGBREAK is generated with Ctrl-Pause on Windows (some laptops have
429
this as Fn-Pause). You can continue execution by typing ``c``. This can
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be disabled if necessary by setting the environment variable
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``BZR_SIGQUIT_PDB=0``.
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Bazaar accepts some global options starting with ``-D`` such as
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``-Dhpss``. These set a value in `bzrlib.debug.debug_flags`, and
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typically cause more information to be written to the trace file. Most
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`mutter` calls should be guarded by a check of those flags so that we
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don't write out too much information if it's not needed.
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Debug flags may have effects other than just emitting trace messages.
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Run ``bzr help global-options`` to see them all.
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These flags may also be set as a comma-separated list in the
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``debug_flags`` option in e.g. ``~/.bazaar/bazaar.conf``. (Note that it
449
must be in this global file, not in the branch or location configuration,
450
because it's currently only loaded at startup time.) For instance you may
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want to always record hpss traces and to see full error tracebacks::
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debug_flags = hpss, error
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511
Because Transports work in URLs (as defined earlier), printing the raw URL
581
512
to the user is usually less than optimal. Characters outside the standard
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513
set are printed as escapes, rather than the real character, and local
583
paths would be printed as ``file://`` urls. The function
514
paths would be printed as ``file://`` URLs. The function
584
515
``unescape_for_display`` attempts to unescape a URL, such that anything
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516
that cannot be printed in the current encoding stays an escaped URL, but
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valid characters are generated where possible.
592
If you'd like to propose a change, please post to the
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bazaar-ng@lists.canonical.com list with a patch, bzr changeset, or link to a
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branch. Please put '[patch]' in the subject so we can pick them out, and
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include some text explaining the change. Remember to put an update to the NEWS
596
file in your diff, if it makes any changes visible to users or plugin
597
developers. Please include a diff against mainline if you're giving a link to
600
Please indicate if you think the code is ready to merge, or if it's just a
601
draft or for discussion. If you want comments from many developers rather than
602
to be merged, you can put '[rfc]' in the subject lines.
604
Anyone is welcome to review code. There are broadly three gates for
607
* Doesn't reduce test coverage: if it adds new methods or commands,
608
there should be tests for them. There is a good test framework
609
and plenty of examples to crib from, but if you are having trouble
610
working out how to test something feel free to post a draft patch
613
* Doesn't reduce design clarity, such as by entangling objects
614
we're trying to separate. This is mostly something the more
615
experienced reviewers need to help check.
617
* Improves bugs, features, speed, or code simplicity.
619
Code that goes in should pass all three.
621
If you read a patch please reply and say so. We can use a numeric scale
622
of -1, -0, +0, +1, meaning respectively "really don't want it in current
623
form", "somewhat uncomfortable", "ok with me", and "please put it in".
624
Anyone can "vote". (It's not really voting, just a terse expression.)
626
If something gets say two +1 votes from core reviewers, and no
627
vetos, then it's OK to come in. Any of the core developers can bring it
628
into their integration branch, which I'll merge regularly. (If you do
629
so, please reply and say so.)
632
Making installers for OS Windows
523
We write some extensions in C using pyrex. We design these to work in
526
* User with no C compiler
527
* User with C compiler
530
The recommended way to install bzr is to have a C compiler so that the
531
extensions can be built, but if no C compiler is present, the pure python
532
versions we supply will work, though more slowly.
534
For developers we recommend that pyrex be installed, so that the C
535
extensions can be changed if needed.
537
For the C extensions, the extension module should always match the
538
original python one in all respects (modulo speed). This should be
539
maintained over time.
541
To create an extension, add rules to setup.py for building it with pyrex,
542
and with distutils. Now start with an empty .pyx file. At the top add
543
"include 'yourmodule.py'". This will import the contents of foo.py into this
544
file at build time - remember that only one module will be loaded at
545
runtime. Now you can subclass classes, or replace functions, and only your
546
changes need to be present in the .pyx file.
548
Note that pyrex does not support all 2.4 programming idioms, so some
549
syntax changes may be required. I.e.
551
- 'from foo import (bar, gam)' needs to change to not use the brackets.
552
- 'import foo.bar as bar' needs to be 'import foo.bar; bar = foo.bar'
554
If the changes are too dramatic, consider
555
maintaining the python code twice - once in the .pyx, and once in the .py,
556
and no longer including the .py file.
559
Making Installers for OS Windows
633
560
================================
634
561
To build a win32 installer, see the instructions on the wiki page:
635
http://bazaar-vcs.org/BzrWin32Installer
638
:: vim: ft=rst tw=74 ai
562
http://wiki.bazaar.canonical.com/BzrWin32Installer
570
What is a Core Developer?
571
-------------------------
573
While everyone in the Bazaar community is welcome and encouraged to
574
propose and submit changes, a smaller team is reponsible for pulling those
575
changes together into a cohesive whole. In addition to the general developer
576
stuff covered above, "core" developers have responsibility for:
579
* reviewing blueprints
581
* managing releases (see `Releasing Bazaar <http://doc.bazaar.canonical.com/developers/releasing.html>`_)
584
Removing barriers to community participation is a key reason for adopting
585
distributed VCS technology. While DVCS removes many technical barriers,
586
a small number of social barriers are often necessary instead.
587
By documenting how the above things are done, we hope to
588
encourage more people to participate in these activities, keeping the
589
differences between core and non-core contributors to a minimum.
592
Communicating and Coordinating
593
------------------------------
595
While it has many advantages, one of the challenges of distributed
596
development is keeping everyone else aware of what you're working on.
597
There are numerous ways to do this:
599
#. Assign bugs to yourself in Launchpad
600
#. Mention it on the mailing list
603
As well as the email notifcations that occur when merge requests are sent
604
and reviewed, you can keep others informed of where you're spending your
605
energy by emailing the **bazaar-commits** list implicitly. To do this,
606
install and configure the Email plugin. One way to do this is add these
607
configuration settings to your central configuration file (e.g.
608
``~/.bazaar/bazaar.conf``)::
611
email = Joe Smith <joe.smith@internode.on.net>
612
smtp_server = mail.internode.on.net:25
614
Then add these lines for the relevant branches in ``locations.conf``::
616
post_commit_to = bazaar-commits@lists.canonical.com
617
post_commit_mailer = smtplib
619
While attending a sprint, RobertCollins' Dbus plugin is useful for the
620
same reason. See the documentation within the plugin for information on
621
how to set it up and configure it.
632
Keeping on top of bugs reported is an important part of ongoing release
633
planning. Everyone in the community is welcome and encouraged to raise
634
bugs, confirm bugs raised by others, and nominate a priority. Practically
635
though, a good percentage of bug triage is often done by the core
636
developers, partially because of their depth of product knowledge.
638
With respect to bug triage, core developers are encouraged to play an
639
active role with particular attention to the following tasks:
641
* keeping the number of unconfirmed bugs low
642
* ensuring the priorities are generally right (everything as critical - or
643
medium - is meaningless)
644
* looking out for regressions and turning those around sooner rather than later.
647
As well as prioritizing bugs and nominating them against a
648
target milestone, Launchpad lets core developers offer to mentor others in
added
removed
doc/developers/HACKING.txt
