问题
Sometimes, when I run a %%cython-cell in an IPython-notebook I get a long backtrace with ends with a quite short error message:
CompileError: command 'gcc' failed with exit status 1
or
LinkError: command 'gcc' failed with exit status 1
On Windows the corresponding messages are:
CompileError: command 'C:.\Microsoft Visual Studio\..\cl.exe' failed with exit status X
and
LinkError: command 'C:..\Microsoft Visual Studio\..\link.exe' failed with exit status YYYY
Is it possible to get more precise information about the underlying error?
An example of such a %%cython-cell follows:
[1] %load_ext Cython
[2] %%cython
from sklearn.tree._tree cimport Node
print("loaded")
回答1:
The %%cython magic uses distutils to build the Cython-extension under the hood and IPython doesn't not capture the output gcc or other compilers/linkers log to standard error/output.
In order to see the errors and warnings logged by the compiler/linker, one must go to the place where the errors are logged to by the compiler, which depends on the way the IPython was started.
IPython/Jupiter notebook:
When the notebook was started from the terminal, e.g. via ipython notebook or similar, then the compiler output can be seen in this terminal - we see that the problem with the above cell is:
/home/ed/.cache/ipython/cython/_cython_magic_5f6d267a6f541c572b4517a74d5c9aad.c:607:31: fatal error:
numpy/arrayobject.h: No such file or directory compilation terminated.
missing numpy-headers, which can be found in numpy.get_include().
IPython-console
If IPython is started from a terminal, the errors are logged directly to the IPython console . But be aware: the compiler/linker outputs will come directly at the beginning of the error-trace:
>>> ipython
Python 3.7.3 (default, Mar 27 2019, 22:11:17)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.4.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]: %load_ext Cython
In [2]: %%cython
...: from sklearn.tree._tree cimport Node
...: print("loaded")
...:
...:
/home/ed/.cache/ipython/cython/_cython_magic_1182f410e5c0a56b03b28dd88700704d.c:607:31: fatal error: numpy/arrayobject.h: No such file or directory
compilation terminated.
---------------------------------------------------------------------------
DistutilsExecError Traceback (most recent call last)
....
CompileError: command 'gcc' failed with exit status 1
The first lines tell us everything we need to know!
Spyder:
At least since Spyder 3.3.3, the output of the compiler/linker is seen in the IPython console (the same as in a standalone IPython-console).
The example %%cython-cell can be fixed as follows:
%%cython -I <path from numpy.get_include()>
from sklearn.tree._tree cimport Node
print("loaded")
来源：https://stackoverflow.com/questions/57726729/what-does-compileerror-linkererror-command-gcc-failed-with-exit-status-1-me