configs/nixos/modules/shell/fish/functions/deploy-to.fish

@@ -34,20 +34,26 @@ if test (count $system_path) -ne 1
     return 1
 end
 
+set closure_paths (nix-store -qR $system_path)
+or begin
+    echo "deploy-to: closure query failed for $host" >&2
+    return $status
+end
+
+echo "deploy-to: checking which closure paths $host is missing" >&2
+set missing_paths (printf '%s\n' $closure_paths | ssh $host 'xargs -r nix-store --check-validity --print-invalid')
+or begin
+    echo "deploy-to: remote closure check failed for $host" >&2
+    return $status
+end
+
+if test (count $missing_paths) -gt 0
     set nar_file (mktemp --suffix=.nar)
     or return $status
     set remote_nar "/tmp/deploy-to-$host-"(date +%s)"-$fish_pid.nar"
 
-set closure_paths (nix-store -qR $system_path)
-or begin
-    set query_status $status
-    rm -f $nar_file
-    echo "deploy-to: closure query failed for $host" >&2
-    return $query_status
-end
-
-echo "deploy-to: exporting closure for $system_path" >&2
-nix-store --export $closure_paths >$nar_file
+    echo "deploy-to: exporting "(count $missing_paths)" missing closure paths for $system_path" >&2
+    nix-store --export $missing_paths >$nar_file
     or begin
         set export_status $status
         rm -f $nar_file
@@ -70,6 +76,9 @@ or begin
         echo "deploy-to: closure import failed for $host" >&2
         return $status
     end
+else
+    echo "deploy-to: $host already has the full closure for $system_path" >&2
+end
 
 echo "deploy-to: activating $system_path on $host" >&2
 ssh -t $host sudo "$system_path/bin/switch-to-configuration" switch