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
aa52c2c0add1'>refs</a><a class='active' href='/guix/log/gnu/bootloader/depthcharge.scm'>log</a><a href='/guix/tree/gnu/bootloader/depthcharge.scm?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1'>tree</a><a href='/guix/commit/gnu/bootloader/depthcharge.scm?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1'>commit</a><a href='/guix/diff/gnu/bootloader/depthcharge.scm?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/bootloader/depthcharge.scm'>
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<div class='path'>path: <a href='/guix/log/?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1'>root</a>/<a href='/guix/log/gnu?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1'>gnu</a>/<a href='/guix/log/gnu/bootloader?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1'>bootloader</a>/<a href='/guix/log/gnu/bootloader/depthcharge.scm?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1'>depthcharge.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/bootloader/depthcharge.scm?id=a8bd933362f6bf26e4a11d062228aa52c2c0add1&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-05-20 08:30:35 -0400'>2020-05-20</span></td><td><a href='/guix/commit/gnu/bootloader/depthcharge.scm?id=b460ba7992a0b4af2ddb5927dcf062784539ef7b'>bootloader: grub: Allow booting from a Btrfs subvolume.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/bootloader/grub.scm (strip-mount-point): Remove procedure.
(normalize-file): Add procedure.
(grub-configuration-file): New BTRFS-SUBVOLUME-FILE-NAME parameter.  When
defined, prepend its value to the kernel and initrd file names, using the
NORMALIZE-FILE procedure.  Adjust the call to EYE-CANDY to pass the
BTRFS-SUBVOLUME-FILE-NAME argument.  Normalize the KEYMAP file as well.
(eye-candy): Add a BTRFS-SUBVOLUME-FILE-NAME parameter, and use it, along with
the NORMALIZE-FILE procedure, to normalize the FONT-FILE and IMAGE nested
variables.  Adjust doc.
* gnu/bootloader/depthcharge.scm (depthcharge-configuration-file): Adapt.
* gnu/bootloader/extlinux.scm (extlinux-configuration-file): Likewise.
* gnu/system/file-systems.scm (btrfs-subvolume?)
(btrfs-store-subvolume-file-name): New procedures.
* gnu/system.scm (operating-system-bootcfg): Specify the Btrfs
subvolume file name the store resides on to the
`operating-system-bootcfg' procedure, using the new
BTRFS-SUBVOLUME-FILE-NAME argument.
* doc/guix.texi (File Systems): Add a Btrfs subsection to document the use of
subvolumes.
* gnu/tests/install.scm (%btrfs-root-on-subvolume-os)
(%btrfs-root-on-subvolume-os-source)
(%btrfs-root-on-subvolume-installation-script)
(%test-btrfs-root-on-subvolume-os): New variables.
</span></span></td><td>Maxim Cournoyer</td></tr>