Another victim of -Werror=implicit-function-declaration being set by default:
make[1]: Entering directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_bakefile/bakefile/work/bakefile-0.2.6'
/bin/sh ./libtool --tag=CC --mode=compile /usr/bin/clang -DPACKAGE_NAME=\"bakefile\" -DPACKAGE_TARNAME=\"bakefile\" -DPACKAGE_VERSION=\"0.2.6\" -DPACKAGE_STRING=\"bakefile\ 0.2.6\" -DPACKAGE_BUGREPORT=\"vslavik@fastmail.fm\" -DPACKAGE=\"bakefile\" -DVERSION=\"0.2.6\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -I. -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -pipe -Os -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -arch x86_64 -MT _bkl_c_la-bkl_c_wrap.lo -MD -MP -MF .deps/_bkl_c_la-bkl_c_wrap.Tpo -c -o _bkl_c_la-bkl_c_wrap.lo `test -f 'src/bkl_c_wrap.c' || echo './'`src/bkl_c_wrap.c
/usr/bin/clang -DPACKAGE_NAME=\"bakefile\" -DPACKAGE_TARNAME=\"bakefile\" -DPACKAGE_VERSION=\"0.2.6\" "-DPACKAGE_STRING=\"bakefile 0.2.6\"" -DPACKAGE_BUGREPORT=\"vslavik@fastmail.fm\" -DPACKAGE=\"bakefile\" -DVERSION=\"0.2.6\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -I. -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -pipe -Os -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -arch x86_64 -MT _bkl_c_la-bkl_c_wrap.lo -MD -MP -MF .deps/_bkl_c_la-bkl_c_wrap.Tpo -c src/bkl_c_wrap.c -fno-common -DPIC -o .libs/_bkl_c_la-bkl_c_wrap.o
src/bkl_c_wrap.c:2853:22: error: implicit declaration of function 'doEvalExpr' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
result = (char *)doEvalExpr((char const *)arg1,arg2,arg3,arg4,arg5,arg6,arg7);
^
src/bkl_c_wrap.c:2853:14: warning: cast to 'char *' from smaller integer type 'int' [-Wint-to-pointer-cast]
result = (char *)doEvalExpr((char const *)arg1,arg2,arg3,arg4,arg5,arg6,arg7);
^
src/bkl_c_wrap.c:2871:24: error: implicit declaration of function 'proxydict_create' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
result = (PyObject *)proxydict_create();
^
src/bkl_c_wrap.c:2871:12: warning: cast to 'PyObject *' (aka 'struct _object *') from smaller integer type 'int' [-Wint-to-pointer-cast]
result = (PyObject *)proxydict_create();
^
src/bkl_c_wrap.c:2889:3: error: implicit declaration of function 'proxydict_hijack' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
proxydict_hijack(arg1,arg2);
^
src/bkl_c_wrap.c:2907:3: error: implicit declaration of function 'proxydict_add' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
proxydict_add(arg1,arg2);
^
2 warnings and 4 errors generated.
make[1]: *** [_bkl_c_la-bkl_c_wrap.lo] Error 1
make[1]: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_bakefile/bakefile/work/bakefile-0.2.6'
make: *** [all-recursive] Error 1
make: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_bakefile/bakefile/work/bakefile-0.2.6'
Command failed: cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_bakefile/bakefile/work/bakefile-0.2.6" && /usr/bin/make -j16 -w all
Exit code: 2
Error: Failed to build bakefile: command execution failed
DEBUG: Error code: CHILDSTATUS 63847 2
This is the well-known implicit declaration of function issue with Xcode 12 and later that needs to be fixed in the usual way (include the right headers in the right places).