introduce new RequirementError (issue2649) This improves the misleading error message $ hg identify abort: there is no Mercurial repository here (.hg not found)! to the more explicit $ hg identify abort: requirement 'fake' not supported! for all commands in commands.optionalrepo, which includes the identify and serve commands in particular. This is for the case when a new entry in .hg/requires will be defined in a future Mercurial release.

Mercurial
=========

Mercurial is a fast, easy to use, distributed revision control tool
for software developers.

Basic install:

 $ make            # see install targets
 $ make install    # do a system-wide install
 $ hg debuginstall # sanity-check setup
 $ hg              # see help

See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.