localrepo: handle ValueError during repository opening

Python 3.8 can raise ValueError on attempt of an I/O operation
against an illegal path. This was causing test-remotefilelog-gc.t
to fail on Python 3.8.

This commit teaches repository opening to handle ValueError
and re-raise an Abort on failure.

An arguably better solution would be to implement this logic
in the vfs layer. But that seems like a bag of worms and I don't
want to go down that rabbit hole. Until users report uncaught
ValueError exceptions in the wild, I think it is fine to patch
this at the only occurrence our test harness is finding it.

Differential Revision: https://phab.mercurial-scm.org/D7944

mercurial/localrepo.py

@@ -509,6 +509,11 b' def makelocalrepository(baseui, path, in'
         except OSError as e:
             if e.errno != errno.ENOENT:
                 raise
+        except ValueError as e:
+            # Can be raised on Python 3.8 when path is invalid.
+            raise error.Abort(
+                _(b'invalid path %s: %s') % (path, pycompat.bytestr(e))
+            )
 
         raise error.RepoError(_(b'repository %s not found') % path)