症状

When users enter their username and password to authenticate with Bitbucket Server, the process just seems to hang with no output:

$ git clone ...
Cloning into ... 
Password:
test123

ソリューション

By default, Git is using functionality available to UNIX, but not available to Cygwin.

The solution is to install an SSH_ASKPASS compatible program for Windows and configure Git to use it.

More details: http://superuser.com/questions/158673/cygwin-git-bizarre-terminal-issue