在OS X上使用错误版本的GCC构建Python

Question

我正在尝试构建python包pycrypto。OS X安装了gcc-4.2，而不是gcc-4.0，但是python继续尝试使用gcc-4.0。如何使用gcc-4.2？或者我应该换一种方式。

我得到以下错误：

bash-3.2$ 
bash-3.2$ sudo python setup.py build
running build
running build_py
running build_ext
warning: GMP library not found; Not building Crypto.PublicKey._fastmath.
building 'Crypto.Hash.MD2' extension
gcc-4.0 -fno-strict-aliasing -fno-common -dynamic -arch ppc -arch i386 -std=c99 -O3 -fomit-frame-pointer -Isrc/ -I/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6 -c src/MD2.c -o build/temp.macosx-10.3-fat-2.6/src/MD2.o
unable to execute gcc-4.0: No such file or directory
error: command 'gcc-4.0' failed with exit status 1
bash-3.2$ 
bash-3.2$ 
bash-3.2$ 

我使用MacOSX10.6.7和Python2.6.6，并安装了XCode。

编辑：如果添加CC=gcc-4.2，则仍然会得到错误：

bash-3.2$ 
bash-3.2$ export CC=gcc-4.2
bash-3.2$ python setup.py build
running build
running build_py
running build_ext
warning: GMP library not found; Not building Crypto.PublicKey._fastmath.
building 'Crypto.Hash.MD2' extension
gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -std=c99 -O3 -fomit-frame-pointer -arch i386 -arch x86_64 -Isrc/ -I/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6 -c src/MD2.c -o build/temp.macosx-10.3-intel-2.6/src/MD2.o
gcc-4.0 -g -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 build/temp.macosx-10.3-intel-2.6/src/MD2.o -o build/lib.macosx-10.3-intel-2.6/Crypto/Hash/MD2.so
unable to execute gcc-4.0: No such file or directory
error: command 'gcc-4.0' failed with exit status 1
bash-3.2$ 

编辑：看来使用sudo在这里会有所不同。

我尝试按照Adam的建议同时使用CC和CXX，在没有sudo的情况下得到以下错误：

bash-3.2$ python setup.py build
running build
running build_py
creating build/lib.macosx-10.3-fat-2.6
creating build/lib.macosx-10.3-fat-2.6/Crypto
copying lib/Crypto/__init__.py -> build/lib.macosx-10.3-fat-2.6/Crypto
copying lib/Crypto/pct_warnings.py -> build/lib.macosx-10.3-fat-2.6/Crypto
...
warning: GMP library not found; Not building Crypto.PublicKey._fastmath.
building 'Crypto.Hash.MD2' extension
creating build/temp.macosx-10.3-fat-2.6
creating build/temp.macosx-10.3-fat-2.6/src
gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -arch ppc -arch i386 -std=c99 -O3 -fomit-frame-pointer -Isrc/ -I/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6 -c src/MD2.c -o build/temp.macosx-10.3-fat-2.6/src/MD2.o
/usr/libexec/gcc/powerpc-apple-darwin10/4.2.1/as: assembler (/usr/bin/../libexec/gcc/darwin/ppc/as or /usr/bin/../local/libexec/gcc/darwin/ppc/as) for architecture ppc not installed
Installed assemblers are:
/usr/bin/../libexec/gcc/darwin/x86_64/as for architecture x86_64
/usr/bin/../libexec/gcc/darwin/i386/as for architecture i386
lipo: can't open input file: /var/tmp//ccxan625.out (No such file or directory)
error: command 'gcc-4.2' failed with exit status 1

如果我使用sudo，当它尝试使用4.0时，会出现以下错误：

bash-3.2$ sudo python setup.py build
Password:
running build
running build_py
running build_ext
warning: GMP library not found; Not building Crypto.PublicKey._fastmath.
building 'Crypto.Hash.MD2' extension
gcc-4.0 -fno-strict-aliasing -fno-common -dynamic -arch ppc -arch i386 -std=c99 -O3 -fomit-frame-pointer -Isrc/ -I/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6 -c src/MD2.c -o build/temp.macosx-10.3-fat-2.6/src/MD2.o
unable to execute gcc-4.0: No such file or directory
error: command 'gcc-4.0' failed with exit status 1
bash-3.2$ 
bash-3.2$ 

这些额外的信息是否让事情变得更加明显，以及如何解决？你知道为什么没有sudo的呼叫会出现另一个错误吗？

Answer 1

请关注此错误：

unable to execute gcc-4.0: No such file or directory
error: command 'gcc-4.0' failed with exit status 1

编译器正准确地告诉您问题所在。gcc-4.0（和gcc-4.2）不在您的PATH中。提示：which gcc-4.2，例如：

% which gcc-4.2
/usr/bin/gcc-4.2

假设你在同一个位置，我不确定为什么/usr/bin不在你的PATH中，但你有它！

找出你的PATH实际上是什么：

% echo $PATH
/opt/local/bin:/bin:/usr/bin:/sbin:/usr/sbin:/usr/bin/X11:/sw/bin:/sw/sbin

修好你的道路，你就会走上启蒙的道路。

Answer 2

顺便说一下，这是一个distutils问题，Python本身不编译任何东西。

正如您所发现的，您可以使用CC环境变量重写编译器。可以重写与CXX环境变量一起使用的链接器。我也想知道为什么distutils会这样做，但事实也是如此。