$ git clone -n https://src.fedoraproject.org/rpms/glycin.git /var/lib/mock/f42-flatpak-app-build-59182266-6571563/root/chroot_tmpdir/scmroot/glycin
Cloning into '/var/lib/mock/f42-flatpak-app-build-59182266-6571563/root/chroot_tmpdir/scmroot/glycin'...
$ git fetch origin b1c1263b4b65dddf73cb70ae85014fc3a42958a0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/glycin
 * [new ref]         b1c1263b4b65dddf73cb70ae85014fc3a42958a0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b1c1263 Update to version 1.2.1; Fixes RHBZ#2359075