title: Can't install numpy with setup.py
body: <p>I'm on Python 2.7 and I'm trying to use the NLTK part of speech tagger, which generates this error because I don't have numpy installed:</p>
  
  <pre><code>&gt; Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/Library/Python/2.7/site-packages/nltk/tag/__init__.py", line 99, in pos_tag
      tagger = load(_POS_TAGGER)
    File "/Library/Python/2.7/site-packages/nltk/data.py", line 605, in load
      resource_val = pickle.load(_open(resource_url))
  ImportError: No module named numpy.core.multiarray
  </code></pre>
  
  <p>So I download numpy 1.7.0 from <a href="http://sourceforge.net/projects/numpy/files/" rel="noreferrer">here</a>, did a cd into my downloads folder and did python setup.py install and got this error:</p>
  
  <pre><code>Running from numpy source directory.
  non-existing path in 'numpy/distutils': 'site.cfg'
  F2PY Version 2
  blas_opt_info:
    FOUND:
      extra_link_args = ['-Wl,-framework', '-Wl,Accelerate']
      define_macros = [('NO_ATLAS_INFO', 3)]
      extra_compile_args = ['-msse3', '-I/System/Library/Frameworks/vecLib.framework/Headers']
  
  lapack_opt_info:
    FOUND:
      extra_link_args = ['-Wl,-framework', '-Wl,Accelerate']
      define_macros = [('NO_ATLAS_INFO', 3)]
      extra_compile_args = ['-msse3']
  
  running install
  running build
  running config_cc
  unifing config_cc, config, build_clib, build_ext, build commands --compiler options
  running config_fc
  unifing config_fc, config, build_clib, build_ext, build commands --fcompiler options
  running build_src
  build_src
  building py_modules sources
  creating build
  creating build/src.macosx-10.6-intel-2.7
  creating build/src.macosx-10.6-intel-2.7/numpy
  creating build/src.macosx-10.6-intel-2.7/numpy/distutils
  building library "npymath" sources
  customize Gnu95FCompiler
  Could not locate executable gfortran
  Could not locate executable f95
  customize NAGFCompiler
  customize AbsoftFCompiler
  Could not locate executable f90
  Could not locate executable f77
  customize IBMFCompiler
  Could not locate executable xlf90
  Could not locate executable xlf
  customize IntelFCompiler
  Could not locate executable ifort
  Could not locate executable ifc
  customize GnuFCompiler
  Could not locate executable g77
  customize G95FCompiler
  Could not locate executable g95
  customize PGroupFCompiler
  Could not locate executable pgfortran
  don't know how to compile Fortran code on platform 'posix'
  C compiler: gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3
  
  compile options: '-Inumpy/core/src/private -Inumpy/core/src -Inumpy/core -Inumpy/core/src/npymath -Inumpy/core/src/multiarray -Inumpy/core/src/umath -Inumpy/core/src/npysort -Inumpy/core/include -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c'
  gcc-4.2: _configtest.c
  sh: gcc-4.2: command not found
  sh: gcc-4.2: command not found
  failure.
  removing: _configtest.c _configtest.o
  Traceback (most recent call last):
    File "setup.py", line 214, in &lt;module&gt;
      setup_package()
    File "setup.py", line 207, in setup_package
      configuration=configuration )
    File "/Users/mikaschiller/Downloads/numpy-1.7.0/numpy/distutils/core.py", line 186, in setup
      return old_setup(**new_attr)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 152, in setup
      dist.run_commands()
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 953, in run_commands
      self.run_command(cmd)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
      cmd_obj.run()
    File "/Users/mikaschiller/Downloads/numpy-1.7.0/numpy/distutils/command/install.py", line 55, in run
      r = old_install.run(self)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/install.py", line 563, in run
      self.run_command('build')
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 326, in run_command
      self.distribution.run_command(command)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
      cmd_obj.run()
    File "/Users/mikaschiller/Downloads/numpy-1.7.0/numpy/distutils/command/build.py", line 37, in run
      old_build.run(self)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/build.py", line 127, in run
      self.run_command(cmd_name)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 326, in run_command
      self.distribution.run_command(command)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
      cmd_obj.run()
    File "/Users/mikaschiller/Downloads/numpy-1.7.0/numpy/distutils/command/build_src.py", line 152, in run
      self.build_sources()
    File "/Users/mikaschiller/Downloads/numpy-1.7.0/numpy/distutils/command/build_src.py", line 163, in build_sources
      self.build_library_sources(*libname_info)
    File "/Users/mikaschiller/Downloads/numpy-1.7.0/numpy/distutils/command/build_src.py", line 298, in build_library_sources
      sources = self.generate_sources(sources, (lib_name, build_info))
    File "/Users/mikaschiller/Downloads/numpy-1.7.0/numpy/distutils/command/build_src.py", line 385, in generate_sources
      source = func(extension, build_dir)
    File "numpy/core/setup.py", line 648, in get_mathlib_info
      raise RuntimeError("Broken toolchain: cannot link a simple C program")
  RuntimeError: Broken toolchain: cannot link a simple C program   
  </code></pre>
  
  <p>I then tried to install it with sudo pip install -U numpy and got the same "cannot link a simple C program" error. I can't figure out what's going on here. Is the numpy version incompatible with python 2.7 or perhaps NLTK?   </p>