$ git clone -n https://src.fedoraproject.org/rpms/rust-signature.git /var/lib/mock/f40-build-2063744-49167/root/chroot_tmpdir/scmroot/rust-signature
Cloning into '/var/lib/mock/f40-build-2063744-49167/root/chroot_tmpdir/scmroot/rust-signature'...
$ git fetch origin ca5bc0f8471d28586fa4ae65f22da5bd10c9b015:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-signature
 * [new ref]         ca5bc0f8471d28586fa4ae65f22da5bd10c9b015 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ca5bc0f Update to version 2.2.0; Fixes RHBZ#2249413