$ git clone -n https://src.fedoraproject.org/rpms/perl-YAML-LibYAML.git /var/lib/mock/f42-build-side-1-3499034-45964/root/chroot_tmpdir/scmroot/perl-YAML-LibYAML
Cloning into '/var/lib/mock/f42-build-side-1-3499034-45964/root/chroot_tmpdir/scmroot/perl-YAML-LibYAML'...
$ git fetch origin 2a08b9762b046138b9c27950cae7c5930bdfa323:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-YAML-LibYAML
 * [new ref]         2a08b9762b046138b9c27950cae7c5930bdfa323 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2a08b97 0.903.0 bump (rhbz#2343445)