$ git clone -n https://src.fedoraproject.org/rpms/libtasn1.git /var/lib/mock/f42-build-side-1-3503824-45982/root/chroot_tmpdir/scmroot/libtasn1
Cloning into '/var/lib/mock/f42-build-side-1-3503824-45982/root/chroot_tmpdir/scmroot/libtasn1'...
$ git fetch origin 443ecb2fe8122c6e8533575ee9f4206a76e66956:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libtasn1
 * [new ref]         443ecb2fe8122c6e8533575ee9f4206a76e66956 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 443ecb2 Update to 4.20.0 upstream release