srd builds a ~/src directory, with subdirectories for sources from different
git forges.

My usage in bash is:

cd `srd https://github.com/alrs/srd`

This checks out the project at https://github.com/alrs/srd and changes to that
directory created under ~/src/github.com/alrs/srd.