fatal: Could not parse object '6f1d67524b18e0a28e681a6c0d0caddf2b59a3ab'.
From https://github.com/NASA-Tensegrity-Robotics-Toolkit/NTRTsim
 * branch            master     -> FETCH_HEAD
HEAD is now at 6f1d675 Switching to MkDocs.
6f1d67524b18e0a28e681a6c0d0caddf2b59a3ab