libstore: add "is dependency" info to goal

whether goal errors are reported via the `ex` member or just printed to
the log depends on whether the goal is a toplevel goal or a dependency.
if goals are aware of this themselves we can move error printing out of
the worker loop, and since a running worker can only be used by running
goals it's totally sufficient to keep a `Worker::running` flag for this

Change-Id: I6b5cbe6eccee1afa5fde80653c4b968554ddd16f

1 files changed, 9 insertions, 1 deletions

diff --git a/src/libstore/build/goal.hh b/src/libstore/build/goal.hh
index 1bfea8231..1f25fb233 100644
--- a/src/libstore/build/goal.hh
+++ b/src/libstore/build/goal.hh
@@ -61,6 +61,13 @@ struct Goal
     Worker & worker;
 
     /**
+      * Whether this goal is only a dependency of other goals. Toplevel
+      * goals that are also dependencies of other toplevel goals do not
+      * set this, only goals that are exclusively dependencies do this.
+      */
+    const bool isDependency;
+
+    /**
      * Goals that this goal is waiting for.
      */
     Goals waitees;
@@ -143,8 +150,9 @@ public:
      */
     std::shared_ptr<Error> ex;
 
-    explicit Goal(Worker & worker)
+    explicit Goal(Worker & worker, bool isDependency)
         : worker(worker)
+        , isDependency(isDependency)
     { }
 
     virtual ~Goal() noexcept(false)