python3 distutils failing in a strange way in _osx_support.py; compiler_so[idx+1]: list index out of range

[mojca (Mojca Miklavec)]

See ​this build log for py36-reportlab:

running build_ext
building 'reportlab.lib._rl_accel' extension
creating build/temp.macosx-10.7-x86_64-3.6
creating build/temp.macosx-10.7-x86_64-3.6/src
creating build/temp.macosx-10.7-x86_64-3.6/src/rl_addons
creating build/temp.macosx-10.7-x86_64-3.6/src/rl_addons/rl_accel
Traceback (most recent call last):
  File "setup.py", line 647, in <module>
    main()
  File "setup.py", line 636, in main
    install_requires=['pillow>=4.0.0'],
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/setuptools/__init__.py", line 145, in setup
    return distutils.core.setup(**attrs)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/core.py", line 148, in setup
    dist.run_commands()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/dist.py", line 955, in run_commands
    self.run_command(cmd)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/dist.py", line 974, in run_command
    cmd_obj.run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/command/build.py", line 135, in run
    self.run_command(cmd_name)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/cmd.py", line 313, in run_command
    self.distribution.run_command(command)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/dist.py", line 974, in run_command
    cmd_obj.run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/setuptools/command/build_ext.py", line 78, in run
    _build_ext.run(self)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/command/build_ext.py", line 339, in run
    self.build_extensions()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/command/build_ext.py", line 448, in build_extensions
    self._build_extensions_serial()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/command/build_ext.py", line 473, in _build_extensions_serial
    self.build_extension(ext)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/setuptools/command/build_ext.py", line 199, in build_extension
    _build_ext.build_extension(self, ext)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/command/build_ext.py", line 533, in build_extension
    depends=ext.depends)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/ccompiler.py", line 574, in compile
    self._compile(obj, src, ext, cc_args, extra_postargs, pp_opts)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/unixccompiler.py", line 115, in _compile
    cc_args + extra_postargs)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/_osx_support.py", line 357, in compiler_fixup
    sysroot = compiler_so[idx+1]
IndexError: list index out of range
Command failed:  cd "/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_python_py-reportlab/py36-reportlab/work/reportlab-3.5.26" && /opt/local/Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6 setup.py --no-user-cfg build 
Exit code: 1

[jmroot (Joshua Root)]

This is a dupe of a few other tickets, one was for mercurial.

[jmroot (Joshua Root)]

#59090