problems installing pycrypto on osx

Question

I'm trying to install a Django project onto my OSX machine, which requires PyCrypto. I'm getting the following error:

running install
running build
running build_py
running build_ext
running build_configure
checking for gcc... no
checking for cc... no
checking for cl.exe... no
configure: error: in `/Users/home/Documents/tmp/dlitz-pycrypto-d2170a4':
configure: error: no acceptable C compiler found in $PATH
See `config.log' for more details
Traceback (most recent call last):
  File "setup.py", line 486, in <module>
    core.setup(**kw)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 152, in setup
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 953, in run_commands
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/install.py", line 573, in run
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 326, in run_command
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/build.py", line 127, in run
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 326, in run_command
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
  File "setup.py", line 292, in run
    self.run_command(cmd_name)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/cmd.py", line 326, in run_command
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
  File "setup.py", line 319, in run
    raise RuntimeError("autoconf error")
RuntimeError: autoconf error

Answer 1

configure: error: no acceptable C compiler found in $PATH

This error is self-explanatory. Get a C compiler.

XCode should work.

Answer 2

If you're using Xcode 4.x on Lion, you'll need to jump through some extra hoops to get this to compile and install:

1) In Xcode, go Preferences > Downloads, and click on the "Install" button next to "Command Line Tools" to install the compiler needed by Python.

2) In my case, I had to create a temporary symbolic link from gcc to gcc-4.2 to get the pycrypto compiler to shut up. In a terminal window, su to get root access:

a) Ensure gcc is installed:

# which gcc
/usr/bin/gcc

b) Create the symbolic link:

# ln -s /usr/bin/gcc /usr/bin/gcc-4.2

3) cd into your pycrypto directory and build and install pycrpto:

# cd ~/Downloads/pycrypto-2.5 (or your version)
# python setup.py build
# python setup.py install

4) Delete the symbolic link you made earlier:

# rm /usr/bin/gcc-4.2

If your process works like mine, you should have a functioning pycrypto installed on Lion.