py*-pykerberos @1.2.1: error: implicit declaration of function 'mempcpy' is invalid in C99

[cooljeanius (Eric Gallager)]

All pykerberos ports fail to upgrade for me with an error from -Werror=implicit-function-declaration:

usr/bin/clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -pipe -Os -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -arch x86_64 -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/opt/local/Library/Frameworks/Python.framework/Versions/3.9/include/python3.9 -c src/kerberosgss.c -o build/temp.macosx-11.2-x86_64-3.9/src/kerberosgss.o -I/opt/local/include -DGSSAPI_EXT
src/kerberosgss.c:876:14: error: implicit declaration of function 'mempcpy' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
    outloc = mempcpy(outloc, iov[1].buffer.value, iov[1].buffer.length);
             ^
src/kerberosgss.c:876:12: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
    outloc = mempcpy(outloc, iov[1].buffer.value, iov[1].buffer.length);
           ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning and 1 error generated.
error: command '/usr/bin/clang' failed with exit code 1
Command failed:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_python_py-pykerberos/py39-pykerberos/work/pykerberos-1.2.1" && /opt/local/Library/Frameworks/Python.framework/Versions/3.9/bin/python3.9 setup.py --no-user-cfg build -j16 
Exit code: 1
Error: Failed to build py39-pykerberos: command execution failed
DEBUG: Error code: CHILDSTATUS 49636 1

[ryandesign (Ryan Carsten Schmidt)]

As far as I can find out, mempcpy is not a standard function and it does not exist on macOS. The developers of pykerberos would need to provide an implementation of it. For example there is an implementation of it in gnulib: ​https://www.gnu.org/software/gnulib/manual/html_node/mempcpy.html

Nevertheless, the build succeeds with just a warning when using Xcode 11 or earlier. I don't understand why the build succeeds or where it's getting an implementation of mempcpy from.

I would like to report this problem to the developers of pykerberos so that they can fix it but I cannot figure out where their homepage or bug tracker are located. They are not mentioned in the README or on the pypi page.

What is mentioned in the README is this:

NOTE: this fork of ccs-kerberos is currently on life support mode as Apple has resumed work on upstream. Please try to use ​https://pypi.python.org/pypi/kerberos instead of this fork if possible.

So perhaps we should switch to that. Perhaps Apple has already fixed the problem in their version. Apple's version is:

​https://github.com/apple/ccs-pykerberos

At least I do not find any occurrences of mempcpy when I search that repo using the GitHub web site.

I don't find any ports depending on py*-pykerberos so at least switching should not impact any other ports.

[ryandesign (Ryan Carsten Schmidt)]

Apple's pykerberos 1.3.1 builds fine for me so I'll update to that.

[ryandesign (Ryan Carsten Schmidt)]

In 2779b12dd91ecf6fc43222a968b412a373b93397/macports-ports (master):

py-pykerberos: Update to 1.3.1

Closes: #62645