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Python: Exit if PYTHONPATH is wrong

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In our sitecustomize.py we instruct python to exit with an error message
if the PYTHONPATH is pointing to a wrong homebrew site-packages dir.
With wrong meaning another major python version.

If you set the PYTHONPATH to include
    $(brew --prefix)/lib/python2.7/site-packages
and start python3, it may pick up modules from there, wich can result
in errors for non pure python modules (such as PyQt).
This commit is contained in:
Samuel John 2013-08-08 11:54:42 +02:00
parent c968f8302f
commit a73012def4
1 changed files with 30 additions and 25 deletions
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55
Library/Homebrew/requirements/python_dependency.rb
View File

@ -288,30 +288,32 @@ class PythonInstalled < Requirement
def sitecustomize
<<-EOF.undent
# This file is created by Homebrew and is executed on each python startup.
# Don't print from here, or else universe will collapse.
# Don't print from here, or else python command line scripts may fail!
# <https://github.com/mxcl/homebrew/wiki/Homebrew-and-Python>
import sys
if sys.version_info[0] == #{version.major} and sys.version_info[1] == #{version.minor}:
if sys.executable.startswith('#{HOMEBREW_PREFIX}/opt/python'):
# Fix 1)
# A setuptools.pth and/or easy-install.pth sitting either in
# /Library/Python/2.7/site-packages or in
# ~/Library/Python/2.7/site-packages can inject the
# /System's Python site-packages. People then report
# "OSError: [Errno 13] Permission denied" because pip/easy_install
# attempts to install into
# /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python
# See: https://github.com/mxcl/homebrew/issues/14712
# Fix 2)
# Remove brewed Python's hard-coded Cellar-site-packages
if sys.version_info[0] != #{version.major}:
import os
# This can only happen if the user has set the PYTHONPATH for 3.x and run Python 2.x or vice versa.
# Every Python looks at the PYTHONPATH variable and we can't fix it here in sitecustomize.py,
# because the PYTHONPATH is evaluated after the sitecustomize.py. Many modules (e.g. PyQt4) are
# built only for a specific version of Python and will fail with cryptic error messages.
# In the end this means: Don't set the PYTHONPATH permanently if you use different Python versions.
exit('Your PYTHONPATH points to a site-packages dir for Python #{version.major}.x but you are running Python ' +
str(sys.version_info[0]) + '.x!\\n PYTHONPATH is currently: "' + str(os.environ['PYTHONPATH']) + '"\\n' +
' You should `unset PYTHONPATH` to fix this.')
else:
# Only do this for a brewed python:
if sys.executable.startswith('#{HOMEBREW_PREFIX}'):
# Remove /System site-packages, and the Cellar site-packages
# which we moved to lib/pythonX.Y/site-packages. Further, remove
# HOMEBREW_PREFIX/lib/python because we later addsitedir(...).
sys.path = [ p for p in sys.path
if not (p.startswith('/System') or
p.startswith('#{HOMEBREW_PREFIX}/Cellar/python') and p.endswith('site-packages')) ]
# Fix 3)
# Set the sys.executable to use the opt_prefix
sys.executable = '#{HOMEBREW_PREFIX}/opt/#{name}/bin/python#{version.major}.#{version.minor}'
# Fix 4)
# Make LINKFORSHARED (and python-config --ldflags) return the
if (not p.startswith('/System') and
not p.startswith('#{HOMEBREW_PREFIX}/lib/python') and
not (p.startswith('#{HOMEBREW_PREFIX}/Cellar/python') and p.endswith('site-packages'))) ]
# LINKFORSHARED (and python-config --ldflags) return the
# full path to the lib (yes, "Python" is actually the lib, not a
# dir) so that third-party software does not need to add the
# -F/#{HOMEBREW_PREFIX}/Frameworks switch.
@ -321,11 +323,14 @@ class PythonInstalled < Requirement
build_time_vars['LINKFORSHARED'] = '-u _PyMac_Error #{HOMEBREW_PREFIX}/opt/#{name}/Frameworks/Python.framework/Versions/#{version.major}.#{version.minor}/Python'
except:
pass # remember: don't print here. Better to fail silently.
# Fix 5)
# For all Pythons of the right major.minor version: Tell about homebrew's
# site-packages location. This is needed for Python to parse *.pth.
# Set the sys.executable to use the opt_prefix
sys.executable = '#{HOMEBREW_PREFIX}/opt/#{name}/bin/#{xy}'
# Tell about homebrew's site-packages location.
# This is needed for Python to parse *.pth.
import site
site.addsitedir('#{global_site_packages}')
site.addsitedir('#{HOMEBREW_PREFIX}/lib/#{xy}/site-packages')
EOF
end