Fix -clear-cache flag when cache is cleared and improve error handling (#176)

* Fix -clear-cache flag when cache is cleared and improve error handling

* Use %q instead of single quotes

Author: mrnugget

cmd/src/actions_cache.go

@@ -89,6 +89,10 @@ func (c actionExecutionDiskCache) clear(ctx context.Context, key actionExecution
 		return err
 	}
 
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		return nil
+	}
+
 	return os.Remove(path)
 }
 

cmd/src/actions_exec_backend_runner.go

@@ -233,7 +233,7 @@ func runAction(ctx context.Context, prefix, repoID, repoName, rev string, steps
 			elapsed := time.Since(t0).Round(time.Millisecond)
 			if err != nil {
 				logger.DockerStepErrored(repoName, i, err, elapsed)
-				return nil, errors.Wrap(err, "run docker container")
+				return nil, errors.Wrapf(err, "Running Docker container for image %q failed", step.Image)
 			}
 			logger.DockerStepDone(repoName, i, elapsed)
 

cmd/src/actions_exec_logger.go

@@ -70,10 +70,14 @@ func (a *actionLogger) ActionFailed(err error, patches []PatchInput) {
 	fmt.Fprintln(os.Stderr)
 	if perr, ok := err.(parallel.Errors); ok {
 		if len(patches) > 0 {
-			yellow.Fprintf(os.Stderr, "✗  Action produced %d patches but failed with %d errors.\n\n", len(patches), len(perr))
+			yellow.Fprintf(os.Stderr, "✗  Action produced %d patches but failed with %d errors:\n\n", len(patches), len(perr))
 		} else {
-			yellow.Fprintf(os.Stderr, "✗  Action failed with %d errors.\n", len(perr))
+			yellow.Fprintf(os.Stderr, "✗  Action failed with %d errors:\n", len(perr))
 		}
+		for _, e := range perr {
+			fmt.Fprintf(os.Stderr, "\t- %s\n", e)
+		}
+		fmt.Println()
 	} else if err != nil {
 		if len(patches) > 0 {
 			yellow.Fprintf(os.Stderr, "✗  Action produced %d patches but failed with error: %s\n\n", len(patches), err)