4レス前は読んだか?

$ hg help convert ~
hg convert [OPTION]... SOURCE [DEST [REVMAP]]

Convert a foreign SCM repository to a Mercurial one.

Accepted source formats:
- Mercurial
- CVS
- Darcs (legacy Darcs 1 format only)
- git
- Subversion
- Monotone
- GNU Arch