PyCrypto builds neither with MSVC nor MinGW

Alec Taylor alec.taylor6 at
Mon Mar 12 21:38:29 CET 2012

On a brand new Windows install now, with a brand new VS8 installed
with new YASM and MPIR in c:\usr\src\include and c:\usr\src\lib.

But it still isn't working:

C:\workingdir\pycrypto>python build_ext -Ic:\usr\src\include
-Lc:\usr\src\lib install
running build_ext
warning: GMP or MPIR library not found; Not building Crypto.PublicKey._fastmath.

building 'Crypto.Random.OSRNG.winrandom' extension
Traceback (most recent call last):
  File "", line 452, in <module>
  File "C:\Python27\lib\distutils\", line 152, in setup
  File "C:\Python27\lib\distutils\", line 953, in run_commands
  File "C:\Python27\lib\distutils\", line 972, in run_command
  File "", line 249, in run
  File "C:\Python27\lib\distutils\command\", line 339, in run
  File "", line 146, in build_extensions
  File "C:\Python27\lib\distutils\command\", line 448, in
  File "C:\Python27\lib\distutils\command\", line 498, in
  File "C:\Python27\lib\distutils\", line 473, in compile
  File "C:\Python27\lib\distutils\", line 383, in initialize
    vc_env = query_vcvarsall(VERSION, plat_spec)
  File "C:\Python27\lib\distutils\", line 299, in
    raise ValueError(str(list(result.keys())))
ValueError: [u'path']

On Wed, Feb 8, 2012 at 11:31 PM, Case Van Horsen <casevh at> wrote:
> On Wed, Feb 8, 2012 at 4:24 AM, Alec Taylor <alec.taylor6 at> wrote:
>> Thanks, but to get it to work with pip, wouldn't I need to add it to
>> PATH? - Or can I just add those library args to pip?
> I don't think so. pyCrypto probably builds a single DLL so the MPIR library is
> statically linked into that DLL. Only the innvocation of should need
> to refer to the MPIR library locations.  I don't use pip so I'm not sure how to
> get pip to install the resulting DLL, etc.
>> On Wed, Feb 8, 2012 at 9:48 PM, Case Van Horsen <casevh at> wrote:
>>> On Tue, Feb 7, 2012 at 9:37 PM, Alec Taylor <alec.taylor6 at> wrote:
>>>> Thanks all for your replies.
>>>> I have now installed MSVC8 and YASM.
>>> I assume you installed Visual Studio. I've omitted the commands to use
>>> the SDK compiler below.
>>>> I was able to successfully run configure.bat and make.bat (including
>>>> make.bat check).
>>>> However, I'm unsure what to do about install, since there is no
>>>> install arg. Do I copy it across to my VC\bin folder, or does it need
>>>> it's own place in PATH + system variables?
>>> The following is just a guess.
>>> I copy the files to a convenient location and then specify that
>>> location to Below is an excerpt from my build process.
>>> mkdir c:\src\lib
>>> mkdir c:\src\include
>>> xcopy /Y mpir.h c:\src\include\*.*
>>> xcopy /Y win\mpir.lib c:\src\lib\*.*
>>> python build_ext -Ic:\src\include -Lc:\src\lib install
>>>> I am asking because I don't know where it is looking for the MPIR library.
>>>> Thanks for all suggestions,
>>>> Alec Taylor

More information about the Python-list mailing list