propagating compiler errors

engine/controller/controller.go

@@ -102,12 +102,12 @@ func (ac *AsyncController) SubmitRequest(runprops *Props) *CtrlRunOutput {
 
 			if runprops.PreRunProps != nil {
 				preRunOut, commandErr := agent.SafeRunCmd(preRunProps)
-				print2.DebugPrintf("error preparing command: output=%v\n \nerror=%v", preRunOut, commandErr)
 				if commandErr != nil {
+					print2.DebugPrintf("error preparing command: output=%v\n \nerror=%v", preRunOut, commandErr)
 					return &CtrlRunOutput{
-						ControllerErr: PreRunError,
-						RunOutput:     nil,
-						CommandErr:    nil,
+						ControllerErr: nil,
+						RunOutput:     preRunOut,
+						CommandErr:    commandErr,
 					}
 				}
 			}

engine/process/main.go

@@ -98,10 +98,25 @@ func main() {
 
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
+
 	err = cmd.Run()
 
 	if err != nil {
 		print.ProcDebug("error running process: %v\n", err)
-		os.Exit(ERunningProc)
+		if cast, ok := err.(*exec.ExitError); ok {
+			if ws, ok := cast.Sys().(syscall.WaitStatus); ok {
+				if ws.Signaled() {
+					// more verbose err message
+					cmd.Stderr.Write([]byte(err.Error()))
+
+					// signal exit code: 128 + signal code
+					os.Exit(128 + int(ws.Signal()))
+				}
+			}
+
+			// if for some reason we can't get the wait status then we
+			// can just get the (probably incorrect) error code from the cast
+			os.Exit(cast.ExitCode())
+		}
 	}
 }

server/api/v2/types.go

@@ -22,5 +22,5 @@ type RunResponse struct {
 	// Stderr is standard error stream from running program
 	Stderr string `json:"stderr"`
 	// Error result from either compilation or runtime errors. Will be nil if both compilation and runtime were successful.
-	Error error `json:"error"`
+	Error string `json:"error"`
 }

server/main.go

@@ -84,7 +84,10 @@ func (rs RunnerServer) runHandler(w http.ResponseWriter, r *http.Request) {
 	output := api.RunResponse{
 		Stdout: RunnerOutput.Stdout,
 		Stderr: RunnerOutput.Stderr,
-		Error:  RunnerOutput.CommandError,
+		// Error:  RunnerOutput.CommandError.Error(),
+	}
+	if RunnerOutput.CommandError != nil {
+		output.Error = RunnerOutput.CommandError.Error()
 	}
 
 	err = json.NewEncoder(w).Encode(output)

web-frontend/js/run-request.js

@@ -19,13 +19,15 @@ function runRequest() {
         reject({
           status: this.status,
           statusText: xhr.statusText,
+          body: xhr.response
         });
       }
     };
     xhr.onerror = function() {
       reject({
         status: this.status,
         statusText: xhr.statusText,
+        body: xhr.response
       });
     };
     xhr.send(JSON.stringify(req));
@@ -65,23 +67,22 @@ async function runCall() {
     .then(function(result) {
       let out = JSON.parse(result);
 
-      out["error"] = stringify(out["error"]);
 
       stdout.innerHTML =
-        "Stdout: " + out["stdout"].replace(/\n/g, "<br>");
+        "<pre>Stdout: " + out["stdout"] + "</pre>";
       stdout.removeAttribute("hidden");
 
       stderr.innerHTML =
-        "Stderr: " + out["stderr"];
+        "<pre>Stderr: " + out["stderr"] + "</pre>";
       stderr.removeAttribute("hidden");
 
-      error.innerHTML = "Error: " + out["error"];
+      error.innerHTML = "<pre>Error: " + out["error"] + "</pre>";
     })
     .catch(function(err) {
       console.log(err);
       stdout.setAttribute("hidden", true);
       stderr.setAttribute("hidden", true);
-      error.innerHTML = "Error: " + stringify(err);
+      error.innerHTML = "<pre>Error: " + stringify(err) + "</pre>";
     });
 }
 

web-frontend/style/main.css

@@ -35,7 +35,7 @@
 
     .field {
         background-color: #d8d8d8;
-        color:#282828;
+        color: #282828;
     }
 }
 
@@ -110,7 +110,11 @@ footer {
     width: 90%;
 }
 
+pre {
+    text-wrap: balance;
+}
+
 #wrapper {
     width: 50%;
     margin-left: 25%;
-}
+}