Subject: bug#22533: Python bytecode reproducibility

From: Ricardo Wurmus <[email-masked]>
Date: Mon, 05 Mar 2018 01:02:15 +0100

Ricardo Wurmus <[email-masked]> writes:

> I have applied this patch locally:
>
> diff --git a/gnu/packages/python.scm b/gnu/packages/python.scm
> index 5f701701a..0d1ecc3c6 100644
> --- a/gnu/packages/python.scm
> +++ b/gnu/packages/python.scm
> @@ -359,8 +359,42 @@ data types.")
>                                "Lib/ctypes/test/test_win32.py" ; fails on aarch64
>                                "Lib/test/test_fcntl.py")) ; fails on aarch64
>                    #t))))
> -    (arguments (substitute-keyword-arguments (package-arguments python-2)
> -                 ((#:tests? _) #t)))
> +    (arguments
> +     (substitute-keyword-arguments (package-arguments python-2)
> +       ((#:tests? _) #t)
> +       ((#:phases phases)
> +        `(modify-phases ,phases
> +           (add-after 'unpack 'patch-timestamp-for-pyc-files
> +             (lambda _
> +               ;; We set DETERMINISTIC_BUILD to only override the mtime when
> +               ;; building with Guix, lest we break auto-compilation in
> +               ;; environments.
> +               (setenv "DETERMINISTIC_BUILD" "1")
> +               (substitute* "Lib/py_compile.py"
> +                 (("source_stats\\['mtime'\\]")
> +                  "(1 if 'DETERMINISTIC_BUILD' in os.environ else source_stats['mtime'])"))
> +
> +               ;; Use deterministic hashes for strings, bytes, and datetime
> +               ;; objects.
> +               (setenv "PYTHONHASHSEED" "0")
> +
> +               ;; Reset mtime when validating bytecode header.
> +               (substitute* "Lib/importlib/_bootstrap_external.py"
> +                 (("source_mtime = int\\(source_stats\\['mtime'\\]\\)")
> +                  "source_mtime = 1"))
> +               #t))
> +           (add-after 'unpack 'disable-timestamp-tests
> +             (lambda _
> +               (substitute* "Lib/test/test_importlib/source/test_file_loader.py"
> +                 (("test_bad_marshal")
> +                  "disable_test_bad_marshal")
> +                 (("test_no_marshal")
> +                  "disable_test_no_marshal")
> +                 (("test_non_code_marshal")
> +                  "disable_test_non_code_marshal"))
> +               #t))
> +           (add-before 'check 'allow-non-deterministic-compilation
> +             (lambda _ (unsetenv "DETERMINISTIC_BUILD") #t))))))
>      (native-search-paths
>       (list (search-path-specification
>              (variable "PYTHONPATH")
>
> It allows me to build python-six and python-sip reproducibly.  It does
> not fix problems with Python 2, and I haven’t yet tested if it causes
> any new problems.

I tested importing modules in an ad-hoc environment — no problems.

Unfortunately, this doesn’t fix all reproducibility problems with numpy:

--8<---------------cut here---------------start------------->8---
Binary files /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0-check/lib/python3.6/site-packages/numpy/distutils/__pycache__/__config__.cpython-36.pyc and /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0/lib/python3.6/site-packages/numpy/distutils/__pycache__/__config__.cpython-36.pyc differ
Binary files /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0-check/lib/python3.6/site-packages/numpy/distutils/__pycache__/exec_command.cpython-36.pyc and /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0/lib/python3.6/site-packages/numpy/distutils/__pycache__/exec_command.cpython-36.pyc differ
Binary files /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0-check/lib/python3.6/site-packages/numpy/distutils/__pycache__/system_info.cpython-36.pyc and /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0/lib/python3.6/site-packages/numpy/distutils/__pycache__/system_info.cpython-36.pyc differ
Binary files /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0-check/lib/python3.6/site-packages/numpy/__pycache__/__config__.cpython-36.pyc and /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0/lib/python3.6/site-packages/numpy/__pycache__/__config__.cpython-36.pyc differ
Binary files /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0-check/lib/python3.6/site-packages/numpy/__pycache__/version.cpython-36.pyc and /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0/lib/python3.6/site-packages/numpy/__pycache__/version.cpython-36.pyc differ
Binary files /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0-check/lib/python3.6/site-packages/numpy/testing/nose_tools/__pycache__/utils.cpython-36.pyc and /gnu/store/kd06ql8fynlydymzhhnwk2lh0778dwcc-python-numpy-1.14.0/lib/python3.6/site-packages/numpy/testing/nose_tools/__pycache__/utils.cpython-36.pyc differ
--8<---------------cut here---------------end--------------->8---

But the successes with simpler Python packages are promising.

--
Ricardo

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