A new script brp-fix-pyc-reproducibility creates an opt-in way of how to fix
problems with the reproducibility of byte-compiled Python files. The script
uses marshalparser [0] which currently doesn't provide solutions for all issues
but can fix at least problems with reference flags. For more info see
this Bugzilla [1].
If you want to use this new feature, you need to define
`%py_reproducible_pyc_path` to specify a path you want to fix `.pyc`
files in (recursively) and build-require /usr/bin/marshalparser.
if you forget to build-require the parser. The error message is:
```
+ /usr/lib/rpm/redhat/brp-python-bytecompile '' 1 0
Bytecompiling .py files below /builddir/build/BUILDROOT/tldr-0.5-2.fc33.x86_64/usr/lib/python3.9 using /usr/bin/python3.9
+ /usr/lib/rpm/redhat/brp-fix-pyc-reproducibility /builddir/build/BUILDROOT/tldr-0.5-2.fc33.x86_64
ERROR: If %py_reproducible_pyc_path is defined, you have to also BuildRequire: /usr/bin/marshalparser !
error: Bad exit status from /var/tmp/rpm-tmp.UUJr4v (%install)
```
A build fails if the parser is not able to parse any of the `.pyc` files.
And finally, if a build is properly configured it produces fixed `.pyc` files.
Currently, `.pyc` files in the tldr package contain a lot of unused reference flags:
```
$ dnf install -y tldr
$ marshalparser --unused /usr/lib/python3.9/site-packages/__pycache__/tldr.cpython-39.pyc
… long output …
190 - Flag_ref(byte=9610, type='TYPE_SHORT_ASCII_INTERNED', content=b'init', usages=0)
191 - Flag_ref(byte=9633, type='TYPE_SHORT_ASCII_INTERNED', content=b'source', usages=0)
192 - Flag_ref(byte=9651, type='TYPE_SHORT_ASCII_INTERNED', content=b'argv', usages=0)
193 - Flag_ref(byte=9657, type='TYPE_SHORT_ASCII_INTERNED', content=b'print_help', usages=0)
194 - Flag_ref(byte=9669, type='TYPE_SHORT_ASCII_INTERNED', content=b'stderr', usages=0)
195 - Flag_ref(byte=9682, type='TYPE_SHORT_ASCII_INTERNED', content=b'parse_args', usages=0)
196 - Flag_ref(byte=9737, type='TYPE_SHORT_ASCII_INTERNED', content=b'encode', usages=0)
197 - Flag_ref(byte=9782, type='TYPE_SHORT_ASCII_INTERNED', content=b'parser', usages=0)
198 - Flag_ref(byte=9790, type='TYPE_SHORT_ASCII_INTERNED', content=b'options', usages=0)
199 - Flag_ref(byte=9799, type='TYPE_SHORT_ASCII_INTERNED', content=b'rest', usages=0)
200 - Flag_ref(byte=9821, type='TYPE_SHORT_ASCII_INTERNED', content=b'result', usages=0)
202 - Flag_ref(byte=10022, type='TYPE_SHORT_ASCII_INTERNED', content=b'__main__', usages=0)
203 - Flag_ref(byte=10102, type='TYPE_SHORT_ASCII_INTERNED', content=b'argparse', usages=0)
204 - Flag_ref(byte=10433, type='TYPE_SHORT_ASCII_INTERNED', content=b'__name__', usages=0)
205 - Flag_ref(byte=10463, type='TYPE_SHORT_ASCII_INTERNED', content=b'<module>', usages=0)
```
This new feature fixes them:
```
$ marshalparser --unused /usr/lib/python3.9/site-packages/__pycache__/tldr.cpython-39.pyc
<empty output>
```
[0] https://github.com/fedora-python/marshalparser
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1686078
This cuts the kernel provide generation time from ~33s to 2.5s on my laptop.
Tighten the path matching rule a bit while at it - it doesn't matter that
much with parametric generator but there's no point looking at entries
we don't generate dependencies on.
Resolves: rhbz#1595265
The problem this change is intended to solve is with how `real_libdir`
is calculated. Let's assume we want to recursively byte-compile all
`*.py` files in
`/builddir/build/BUILDROOT/python-scales-1.0.9-250.fc32.x86_64/usr/lib/python3.8`.
Then, `real_libdir` is this path without `$RPM_BUILD_ROOT` with
the filename at the end which displays in the error message like this:
```
Bytecompiling .py files below /builddir/build/BUILDROOT/python-scales-1.0.9-250.fc32.x86_64/usr/lib/python3.8 using /usr/bin/python3.8
*** Error compiling '/builddir/build/BUILDROOT/python-scales-1.0.9-250.fc32.x86_64/usr/lib/python3.8/site-packages/greplin/bar.py'...
File "/usr/lib/python3.8/bar.py", line 1
import sin from math
^
SyntaxError: invalid syntax
```
`/usr/lib/python3.8/bar.py` is obviously wrong.
One of the new features of the `compileall2` module (which will
be available in stdlib in Python 3.9) is that the path byte-compiled to
`*.pyc` files is calculated for each file. This means that by using
`-s` and `-p` we can strip `$RPM_BUILD_ROOT` and prepend `/` for each
file individually which will fix the problem.
```
Bytecompiling .py files below /builddir/build/BUILDROOT/python-scales-1.0.9-250.fc32.x86_64/usr/lib/python3.8 using /usr/bin/python3.8
*** Error compiling '/builddir/build/BUILDROOT/python-scales-1.0.9-250.fc32.x86_64/usr/lib/python3.8/site-packages/greplin/bar.py'...
File "/usr/lib/python3.8/site-packages/greplin/bar.py", line 1
import sin from math
^
SyntaxError: invalid syntax
```
This change has an effect only for Python >= 3.4.
If %source_date_epoch_from_changelog is true, RPM can set the SOURCE_DATE_EPOCH
environment variable to the timestamp of the topmost changelog entry. The
SOURCE_DATE_EPOCH can be in turn used by various projects to override otherwise
dynamically generated timestamps.
E.g. this might help to have stable timestamps in generated
documentation etc.
Rpm 4.15 removes various language-specific macros. Python side is
already covered by the versioned python macros but this is not the
case with Perl, macros. Add them here temporarily to avoid breaking
the world, but these really belong to perl-macros or such.
Once upon a time these did differ (for various bad reasons) but the
version in rpm has been identical to ours for many years, lets shed
some old baggage.
Tom Stellard
Lumir Balhar
Jeff Law
Igor Raits
Nicolas Mailhot
Jason Tibbitts
Panu Matilainen
Florian Weimer
Denys Vlasenko
Miro Hrončok
Richard W.M. Jones
Robert-André Mauchin
Florian Festi
Daniel Mach
Vít Ondruch
Jitka Plesnikova
Björn Persson