debugshell extension
After enabling the extension, "hg debugshell" or "hg dbsh" will drop user into an interactive python shell along with the mercurial module, a repo object and its changelog & manifest.
The extension is available in the main repo: contrib/debugshell.py
$ hg debugshell loaded repo : /path/to/repo using source: /path/to/mercurial/source >>> repo <mercurial.localrepo.localrepository object at 0x0> >>> cl <mercurial.changelog.changelog object at 0x0> >>> mnfst <mercurial.manifest.manifest object at 0x0> >>> mercurial <proxied module 'mercurial'> >>>