prepare-commit-message adds to commit message branch name, which can be parsed be Bitbucket. It works with every git's GUIs. If you work on Windows you should install grep, awk and sed tool.
To install globally, copy prepare-commit-msg to /usr/local/share/git-core/templates/hooks and execute:
chmod +x /usr/local/share/git-core/templates/hooks/prepare-commit-msg
To install per-repository, copy prepare-commit-msg to /path/to/repo/.git/hooks/prepare-commit-msg and mark it as executable.
Hooks need to be executable, so you may need to change the file permissions of the script if you’re creating it from scratch. For example, to make sure that prepare-commit-msg is executable, you would run the following command:
chmod +x prepare-commit-msg
The branch name will be automatically appended to commit messages using git commit or git commit -m "message".
If you'd like to use this commit message hook in an existing repository, after copying the file to the proper location, run git init within the repository for the hook to be initialized.
On the basis of Jim Schubert's code.