Bug#1066042: python-quantities: please make the build reproducible

[Chris Lamb]

Source: python-quantities
Version: 0.15.0-1
Severity: wishlist
Tags: patch
User: reproducible-builds at lists.alioth.debian.org
Usertags: timestamps
X-Debbugs-Cc: reproducible-bugs at lists.alioth.debian.org

Hi,

Whilst working on the Reproducible Builds effort [0], we noticed that
python-quantities could not be built reproducibly.

This is because the build process writes a timestamp to a generated
file. A patch is attached that sources this timestamp from SOURCE_DATE_EPOCH
instead of the system clock.

 [0] https://reproducible-builds.org/


Regards,

-- 
      ,''`.
     : :'  :     Chris Lamb
     `. `'`      lamby at debian.org / chris-lamb.co.uk
       `-
-------------- next part --------------
--- a/debian/patches/reproducible-build.patch	1970-01-01 01:00:00.000000000 +0100
--- b/debian/patches/reproducible-build.patch	2024-03-11 15:07:58.203181306 +0000
@@ -0,0 +1,31 @@
+Description: Make the build reproducible
+Author: Chris Lamb <lamby at debian.org>
+Last-Update: 2024-03-11
+
+--- python-quantities-0.15.0.orig/setup.py
++++ python-quantities-0.15.0/setup.py
+@@ -1,8 +1,14 @@
++import os
++import time
+ from setuptools import Command, setup
+ from setuptools.command.build_py import build_py as _build
+ from setuptools.command.sdist import sdist as _sdist
+-from datetime import datetime
++from datetime import datetime, timezone
+ 
++build_date = datetime.fromtimestamp(
++    int(os.environ.get('SOURCE_DATE_EPOCH', time.time())),
++    tz=timezone.utc,
++)
+ 
+ class data(Command):
+ 
+@@ -24,7 +30,7 @@ class data(Command):
+         with open('quantities/constants/_codata.py', 'w') as f:
+             f.write('# THIS FILE IS AUTOMATICALLY GENERATED\n')
+             f.write('# ANY CHANGES MADE HERE WILL BE LOST\n')
+-            f.write(f'# LAST GENERATED: {datetime.now()}\n\n')
++            f.write(f'# LAST GENERATED: {build_date}\n\n')
+             f.write('physical_constants = {}\n\n')
+             for line in data:
+                 name = line[:55].rstrip().replace('mag.','magnetic')
--- a/debian/patches/series	1970-01-01 01:00:00.000000000 +0100
--- b/debian/patches/series	2024-03-11 15:05:38.702459132 +0000
@@ -0,0 +1 @@
+reproducible-build.patch