Test the queue runner in the scenario where a dependency is available in the cache but GC'd locally, where we're building locally

t/jobs/dependencies/dependency.nix

@@ -0,0 +1,17 @@
+{ exposeUnderlyingJob, exposeDependentJob }:
+with import ../config.nix;
+let
+  underlyingJob = mkDerivation {
+    name = "underlying-job";
+    builder = ../empty-dir-builder.sh;
+  };
+
+  dependentJob = mkDerivation {
+    name = "dependent-job";
+    builder = ../empty-dir-builder.sh;
+    inherit underlyingJob;
+  };
+in
+(if exposeUnderlyingJob then { inherit underlyingJob; } else { }) //
+(if exposeDependentJob then { inherit dependentJob; } else { }) //
+{ }