$ git clone -n https://src.fedoraproject.org/rpms/libicu77.git /var/lib/mock/f45-build-16446-486/root/chroot_tmpdir/scmroot/libicu77
Cloning into '/var/lib/mock/f45-build-16446-486/root/chroot_tmpdir/scmroot/libicu77'...
$ git fetch origin 7680d5b0f51bc6f45d7b377c59ec8677bcb068c3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libicu77
 * [new ref]         7680d5b0f51bc6f45d7b377c59ec8677bcb068c3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7680d5b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild