diff --git a/ofborg/src/tasks/build.rs b/ofborg/src/tasks/build.rs
index 2a96337..d8784de 100644
--- a/ofborg/src/tasks/build.rs
+++ b/ofborg/src/tasks/build.rs
@@ -55,6 +55,7 @@ pub struct JobActions<'a, 'b> {
     receiver: &'a mut notifyworker::NotificationReceiver,
     job: &'b buildjob::BuildJob,
     line_counter: u64,
+    snippet_log: VecDeque<String>,
     attempt_id: String,
     log_exchange: Option<String>,
     log_routing_key: Option<String>,
@@ -86,6 +87,7 @@ impl<'a, 'b> JobActions<'a, 'b> {
             receiver: receiver,
             job: job,
             line_counter: 0,
+            snippet_log: VecDeque::with_capacity(10),
             attempt_id: format!("{}", Uuid::new_v4()),
             log_exchange: log_exchange,
             log_routing_key: log_routing_key,
@@ -94,6 +96,10 @@ impl<'a, 'b> JobActions<'a, 'b> {
         };
     }
 
+    pub fn log_snippet(&self) -> VecDeque<String> {
+        self.snippet_log.clone()
+    }
+
     pub fn commit_missing(&mut self) {
         self.tell(worker::Action::Ack);
     }
@@ -149,9 +155,25 @@ impl<'a, 'b> JobActions<'a, 'b> {
         ));
     }
 
+    pub fn log_instantiation_errors(&mut self, cannot_build: Vec<(String, Vec<String>)>) {
+        for (attr, log) in cannot_build {
+            self.log_line(&format!("Cannot nix-instantiate `{}' because:", &attr));
+
+            for line in log {
+                self.log_line(&line);
+            }
+            self.log_line("");
+        }
+    }
+
     pub fn log_line(&mut self, line: &str) {
         self.line_counter += 1;
 
+        if self.snippet_log.len() >= 10 {
+            self.snippet_log.pop_front();
+        }
+        self.snippet_log.push_back(line.to_owned());
+
         let msg = buildlogmsg::BuildLogMsg {
             identity: self.identity.clone(),
             system: self.system.clone(),
@@ -340,17 +362,7 @@ impl notifyworker::SimpleNotifyWorker for BuildWorker {
         let acmd = AsyncCmd::new(cmd);
         let mut spawned = acmd.spawn();
 
-        let mut snippet_log = VecDeque::with_capacity(10);
-
-
-
         for line in spawned.lines().iter() {
-
-            if snippet_log.len() >= 10 {
-                snippet_log.pop_front();
-            }
-
-            snippet_log.push_back(line.to_owned());
             actions.log_line(&line);
         }
 
@@ -364,10 +376,10 @@ impl notifyworker::SimpleNotifyWorker for BuildWorker {
 
         println!("ok built ({:?}), building", success);
         println!("Lines:\n-----8<-----");
-        snippet_log.iter().inspect(|x| println!("{}", x)).last();
+        actions.log_snippet().iter().inspect(|x| println!("{}", x)).last();
         println!("----->8-----");
 
-        let last10lines: Vec<String> = snippet_log.into_iter().collect::<Vec<String>>();
+        let last10lines: Vec<String> = actions.log_snippet().into_iter().collect::<Vec<String>>();
 
         actions.build_finished(success, last10lines.clone(), can_build, cannot_build);
         println!("Done!");