path: forbid chaining `path://` definitions...
path: forbid chaining `path://` definitions
To have `path://xxx` referencing paths that use `path://` too, we need to
analyze dependencies to initialize them in the right order (and to detect
cycle).
I don't want to deal with that right now, so I just disallow it for now.
Differential Revision:
https://phab.mercurial-scm.org/D10264
