$ git clone -n https://src.fedoraproject.org/rpms/libksba.git /var/lib/mock/f40-build-785666-134041/root/chroot_tmpdir/scmroot/libksba
Cloning into '/var/lib/mock/f40-build-785666-134041/root/chroot_tmpdir/scmroot/libksba'...
$ git fetch origin f8d18d14386206bc6083d0da39ebc3dca93cafd8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libksba
 * [new ref]         f8d18d14386206bc6083d0da39ebc3dca93cafd8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f8d18d1 1.6.6-1