$ git clone -n https://src.fedoraproject.org/rpms/perl-Exception-Base.git /var/lib/mock/f45-build-23418-597/root/chroot_tmpdir/scmroot/perl-Exception-Base
Cloning into '/var/lib/mock/f45-build-23418-597/root/chroot_tmpdir/scmroot/perl-Exception-Base'...
$ git fetch origin 8473a8dfe5f33135b3fddfeab105b6d3f0d9c23f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Exception-Base
 * [new ref]         8473a8dfe5f33135b3fddfeab105b6d3f0d9c23f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8473a8d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild