localrepo: better error when a repo exists but we lack permissions

Claiming "repository foo not found" when the repository does exist
causes confusion regularly ("where is the typo?").

Differential Revision: https://phab.mercurial-scm.org/D4122

mercurial/localrepo.py

@@ -495,6 +495,11 b' class localrepository(object):'
                         ' dummy changelog to prevent using the old repo layout'
                     )
             else:
+                try:
+                    self.vfs.stat()
+                except OSError as inst:
+                    if inst.errno != errno.ENOENT:
+                        raise
                 raise error.RepoError(_("repository %s not found") % path)
         elif create:
             raise error.RepoError(_("repository %s already exists") % path)

tests/test-clone.t

@@ -642,7 +642,7 b' Inaccessible source'
   $ mkdir a
   $ chmod 000 a
   $ hg clone a b
-  abort: repository a not found!
+  abort: Permission denied: '$TESTTMP/fail/a/.hg'
   [255]
 
 Inaccessible destination
@@ -665,7 +665,7 b' Source of wrong type'
 
   $ mkfifo a
   $ hg clone a b
-  abort: repository a not found!
+  abort: $ENOTDIR$: '$TESTTMP/fail/a/.hg'
   [255]
   $ rm a