Load pep517 from devpi. Update to newer API.

Author: jaraco

importlib_metadata/__init__.py

@@ -199,9 +199,10 @@ def _discover_resolvers():
 
     @classmethod
     def find_local(cls, root='.'):
+        import pep517.build as build
         import pep517.build_meta as bm
-        system = bm.compat_build_system(root)
-        builder = functools.partial(bm.build_meta, build_system=system)
+        system = build.compat_system(root)
+        builder = functools.partial(bm.build_meta, system=system)
         return PathDistribution(zipp.Path(bm.build_meta_as_zip(builder)))
 
     @property

tox.ini

@@ -32,8 +32,9 @@ deps =
      py27: contextlib2
      pip >= 18
      packaging
-     git+https://github.com/pypa/pep517@feature/build-meta-command
+     pep517
 setenv =
+    PIP_INDEX_URL=https://m.devpi.net/jaraco/pep517-meta
     cov: COVERAGE_PROCESS_START={[coverage]rcfile}
     cov: COVERAGE_OPTIONS="-p"
     cov: COVERAGE_FILE={toxinidir}/.coverage