To enable ssh : System Preferences/Sharing/Remote Login

To allow connection without password, put the keys in /.ssh/authorized_keys (file and directory have to created).

brew install hg

or

brew install mercurial

On installation ending, the following message is displayed, which apparently can be safely ignored for a simple use of mercurial :

Python modules have been installed and Homebrew's site-packages is not
in your Python sys.path, so you will not be able to import the modules
this formula installed. If you plan to develop with these modules,
please run:
  mkdir -p /Users/csimon/Library/Python/2.7/lib/python/site-packages
  echo 'import site; site.addsitedir("/usr/local/lib/python2.7/site-packages")' >> /Users/csimon/Library/Python/2.7/lib/python/site-packages/homebrew.pth

By default, some tools have to be launched with sudo to work correctly. This concerns namely :

• dtruss,
• gdb-apple (GNU debugger).

To allow them to work properly without sudo, change their permissions the following way :

sudo chmod u+s <path to bin>

Be careful : this can be an important security issue !