_decimal fails to build on my platform due to lack of support:

In file included from /Developer/Python/3.6/Python/Python-3.6.5/Modules/_decimal/_decimal.c:34:
/usr/local/include/mpdecimal.h:201:4: error: "unsupported platform: need mpd_size_t == mpd_uint_t"
  #error "unsupported platform: need mpd_size_t == mpd_uint_t"

My host system type: x86_64-apple-darwin17.5.0
My target system type: x86_64-apple-darwin17.5.0
Compiler used: clang+llvm-6.0.0-x86_64-apple-darwin
Hardware: 3,7 GHz Quad-Core Intel Xeon E5

Relevant configurations:

--enable-universalsdk... /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk

--with-universal-archs... intel

MACHDEP... darwin

Could this module be upgraded?

I don't have OS X. However, this is the first time in 6 years that anyone has reported an OS X build failure.

Perhaps Ned knows the answer.

> However, this is the first time in 6 years that anyone has reported an OS X build failure.

Yes, I've never seen one before, either.

But I think the culprit is pointed to in the error message.  It looks like you have another version of mpdecimal in /usr/local/.

This is correct: I had an older version of mpdecimal in /usr/local. However, when removed mpdecimal is (manually) removed from /usr/local (the libs and the header), making a "make clean", a config and make, the _decimal build still fails, but this time for a different reason:

/Developer/Python/3.6/Python/Python-3.6.5/Modules/_decimal/_decimal.c:34:10: fatal error: 'mpdecimal.h' file not found
#include "mpdecimal.h"

Still, we are getting closer: should I install a newer version of mpdecimal and try again?

It looks to me as if you are compiling --with-system-libmpdec.

You don't need that, libmpdec is included in the Python tarball.

-with-system-libmpdec was added mainly for Linux distros.  If there's a widespread interest to support it on OS X, I'd need a patch.



A hack that should work is "export PYTHON_DECIMAL_WITH_MACHINE=universal" during the Python build, then the external libmpdec *might* work.

This flag was mainly added for testing. Note that "universal" does not always build fat binaries -- it uses whatever Python is configured with.

Another source of error is of course if the external libmpdec was not compiled as "universal" but Python is.

I'm trying to reduce the number of open issues that I'm involved in.

If something concrete comes up, feel free to reopen.

Yes, the error turned out to be that I had indeed forgotten to remove the --with-system-libmpdec along with the library and header. Now _decimal compiles fine. I will see if I can get Python to run with my system's mpdecimal (once I have updated it), but as far as this issue is concerned I believe it is indeed closed. Thanks for the help!