Mercurial は Mavericks (Python 3) では動作しないようです。誰もが解決策を見つけます。
abort: couldn't find mercurial libraries in [
/Library/Python/2.7/site-packages/
/usr/local/bin
/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip
/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7
/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac
/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages
/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python
/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old
/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC
/Library/Python/2.7/site-packages
]
(check your install and PYTHONPATH)