Most apple system frameworks do not have a Versions directory in them at
all.
Fixes the following traceback:
...
File "/Users/matt/Projects/cerbero/build/build-tools/lib/python3.7/site-packages/meson-0.51.999-py3.7.egg/mesonbuild/interpreter.py", line 3063, in func_dependency
d = self.dependency_impl(name, display_name, kwargs)
File "/Users/matt/Projects/cerbero/build/build-tools/lib/python3.7/site-packages/meson-0.51.999-py3.7.egg/mesonbuild/interpreter.py", line 3110, in dependency_impl
dep = dependencies.find_external_dependency(name, self.environment, kwargs)
File "/Users/matt/Projects/cerbero/build/build-tools/lib/python3.7/site-packages/meson-0.51.999-py3.7.egg/mesonbuild/dependencies/base.py", line 2142, in find_external_dependency
d = c()
File "/Users/matt/Projects/cerbero/build/build-tools/lib/python3.7/site-packages/meson-0.51.999-py3.7.egg/mesonbuild/dependencies/base.py", line 2004, in __init__
self.detect(name, paths)
File "/Users/matt/Projects/cerbero/build/build-tools/lib/python3.7/site-packages/meson-0.51.999-py3.7.egg/mesonbuild/dependencies/base.py", line 2035, in detect
incdir = self._get_framework_include_path(framework_path)
File "/Users/matt/Projects/cerbero/build/build-tools/lib/python3.7/site-packages/meson-0.51.999-py3.7.egg/mesonbuild/dependencies/base.py", line 2065, in _get_framework_include_path
self._get_framework_latest_version(path))
File "/Users/matt/Projects/cerbero/build/build-tools/lib/python3.7/site-packages/meson-0.51.999-py3.7.egg/mesonbuild/dependencies/base.py", line 2057, in _get_framework_latest_version
return 'Versions/{}/Headers'.format(sorted(versions)[-1]._s)
IndexError: list index out of range