Add all /gnu/store/ prefixes found in PYTHONPATH to the prefixes where
site-packages (and .pth files) are searched.

*** Python-2.7.11/Lib/site.py.orig	2016-10-17 23:27:23.746149690 +0200
--- Python-2.7.11/Lib/site.py	2016-10-17 23:44:51.930871644 +0200
***************
*** 65,70 ****
--- 65,82 ----
  
  # Prefixes for site-packages; add additional prefixes like /usr/local here
  PREFIXES = [sys.prefix, sys.exec_prefix]
+ # Guix: Add all /gnu/store-paths in PYTHONPATH--these are all
+ # "prefixes".  This is required to search .pth files in all python
+ # packages contained in /gnu/store which is required to make
+ # .pth-defined namespace packages work.
+ # This is necessary if the packages are not merged into a single
+ # `site-packages` directory (like when using `guix environment`) but
+ # listed in PYTHONPATH (like when running `guix build`).
+ for p in sys.path:
+     if p.startswith('/gnu/store/'):
+         PREFIXES.append(p[:p.find('/', 44)]) # find first pathsep after hash
+ del p
+ 
  # Enable per user site-packages directory
  # set it to False to disable the feature or True to force the feature
  ENABLE_USER_SITE = None
a608666d74f156819cecfabaf72290726d7964e6'>refs</a><a class='active' href='/guix/log/gnu/packages/patches/ilmbase-fix-tests.patch'>log</a><a href='/guix/tree/gnu/packages/patches/ilmbase-fix-tests.patch?id=a608666d74f156819cecfabaf72290726d7964e6'>tree</a><a href='/guix/commit/gnu/packages/patches/ilmbase-fix-tests.patch?id=a608666d74f156819cecfabaf72290726d7964e6'>commit</a><a href='/guix/diff/gnu/packages/patches/ilmbase-fix-tests.patch?id=a608666d74f156819cecfabaf72290726d7964e6'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/patches/ilmbase-fix-tests.patch'>
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<tr><td><span title='2019-09-24 20:12:56 +0200'>2019-09-24</span></td><td><a href='/guix/commit/gnu/packages/patches/ilmbase-fix-tests.patch?id=942c7889498fc8e680a16d500e166c9ade84e640'>gnu: OpenEXR: Update to 2.4.0 [fixes CVE-2018-18443, CVE-2018-18444].</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/patches/ilmbase-fix-tests.patch: Adjust for new origin.
* gnu/packages/patches/ilmbase-openexr-pkg-config.patch: New file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
* gnu/packages/graphics.scm (ilmbase): Update to 2.4.0.
[source]: Change to GIT-FETCH, as tarballs are no longer provided.  Add new
patch.
[build-system]: Change to CMAKE-BUILD-SYSTEM.
[arguments]: Add phase to enter the correct source directory.
* gnu/packages/graphics.scm (openexr): Update to 2.4.0.
[source]: Inherit from ILMBASE, which comes from the same repository.
[build-system]: Change to CMAKE-BUILD-SYSTEM.
[arguments]: Add phase to enter the correct source directory.
* gnu/packages/gstreamer.scm (gst-plugins-bad)[arguments]: Enable C++11.
* gnu/packages/image-processing.scm (opencv)[arguments]: Likewise.
</span></span></td><td>Marius Bakke</td></tr>