[NumPy-Tickets] [NumPy] #2194: Gnu95FCompiler doesn't find libmingwex.a when using msvc + gfortran

[NumPy Trac]

#2194: Gnu95FCompiler doesn't find libmingwex.a when using msvc + gfortran
---------------------------------------+------------------------------------
 Reporter:  stevenwinfield             |       Owner:  cdavid     
     Type:  defect                     |      Status:  new        
 Priority:  normal                     |   Milestone:  Unscheduled
Component:  numpy.distutils            |     Version:  1.6.1      
 Keywords:  win32 msvc gfortran mingw  |  
---------------------------------------+------------------------------------
 (This is actually a bug in 1.6.2, but I couldn't select that)

 A MingW installation is laid out as follows:

 {{{
 MingW
 | - lib
 |   | - libmingw32.a
 |   | - libmingwex.a
 |   | - gcc
 |       | - mingw32
 |           | - <version number>
 |               | - libgcc.a
 | - mingw32
     | - lib
         | - ...
 }}}

 In numpy/distutils/fcompiler/gnu.py, in the get_library_dirs() method of
 Gnu95FCompiler (beginning line 299) the code first gets the libgcc
 directory then tries to navigate to the directory containing libmingwex.a
 by doing the following:

 {{{
 d = os.path.normpath(self.get_libgcc_dir())
 root = os.path.join(d, os.pardir, os.pardir, os.pardir, os.pardir)
 mingwdir = os.path.normpath(os.path.join(root, target, "lib"))
 }}}

 "target" here is "mingw32", so mingwdir is "MingW\mingw32\lib", which
 exists but doesn't contain libmingwex.a. If "target" were to be removed
 from the last line then all would be fine.

 This problem manifests itself when trying to build scipy, with the error
 message:
 {{{
 LINK : fatal error LNK1181: cannot open input file 'mingw32.lib'
 }}}

 This is because a few MingW .a files are copied (by
 _libs_with_msvc_and_fortran() in numpy/distutils/command/build_ext.py) to
 .lib files in a temporary build directory so that they can be found by
 msvc - one of which should be libmingw32.a => mingw32.lib. However, the .a
 file is never found and so the copying never takes place.

-- 
Ticket URL: <http://projects.scipy.org/numpy/ticket/2194>
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