$ git clone -n https://src.fedoraproject.org/rpms/gnome-shell-extensions.git /var/lib/mock/f42-build-side-1-3498280-45962/root/chroot_tmpdir/scmroot/gnome-shell-extensions
Cloning into '/var/lib/mock/f42-build-side-1-3498280-45962/root/chroot_tmpdir/scmroot/gnome-shell-extensions'...
$ git fetch origin 1e2b4884137812c77a810c7c551925cc49c0c096:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-shell-extensions
 * [new ref]         1e2b4884137812c77a810c7c551925cc49c0c096 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1e2b488 Update to 48.1