services/nomad/build/buildbot: fix syncing packages multiple times

Author: classabbyamp

services/nomad/build/buildbot.cfg

@@ -219,10 +219,17 @@ def make_xbps_bulk_cmd(props):
 
 @util.renderer
 def make_rsync_cmd(props):
+    target = props.getProperty('target')
+    if target.startswith("aarch64"):
+        final_dest = "/mirror/current/aarch64/"
+    elif target.endswith("musl"):
+        final_dest = "/mirror/current/musl/"
+    else:
+        final_dest = "/mirror/current/"
     return ['bash', '-e', '-c',
-            util.Interpolate("""
+            util.Interpolate(f"""
 echo "=> Syncing packages to the shadow repository..."
-rsync -vurk --delete-after \
+rsync -vurk --delete-after --compare-dest={final_dest} \
 --filter='+ */' --filter='+ *.%(prop:target)s.xbps' \
 --filter='- .*' --filter='- *' \
 --password-file=/secrets/rsync/password /hostdir/binpkgs/ \