$ git clone -n https://src.fedoraproject.org/rpms/python-boto3.git /var/lib/mock/f42-build-side-1-3523456-46206/root/chroot_tmpdir/scmroot/python-boto3
Cloning into '/var/lib/mock/f42-build-side-1-3523456-46206/root/chroot_tmpdir/scmroot/python-boto3'...
$ git fetch origin 5ffb151f3ecc4efb4a7d56173bcb54c6af55729f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-boto3
 * [new ref]         5ffb151f3ecc4efb4a7d56173bcb54c6af55729f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5ffb151 1.38.2