From 8565a30c690a25b491e5383dc8a231c5f05d0940 Mon Sep 17 00:00:00 2001
From: Adrien Delorme <adrien.delorme@icloud.com>
Date: Tue, 9 Apr 2019 15:29:07 +0200
Subject: [PATCH] TimeoutProvisioner: also display an error log when the
 context times out

---
 packer/provisioner_timeout.go | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/packer/provisioner_timeout.go b/packer/provisioner_timeout.go
index a2af71e7a..1da02f563 100644
--- a/packer/provisioner_timeout.go
+++ b/packer/provisioner_timeout.go
@@ -19,5 +19,25 @@ func (p *TimeoutProvisioner) Provision(ctx context.Context, ui Ui, comm Communic
 
 	// Use a select to determine if we get cancelled during the wait
 	ui.Say(fmt.Sprintf("Setting a %s timeout for the next provisioner...", p.Timeout))
-	return p.Provisioner.Provision(ctx, ui, comm)
+
+	errC := make(chan interface{})
+
+	go func() {
+		select {
+		case <-errC:
+			// all good
+		case <-ctx.Done():
+			switch ctx.Err() {
+			case context.DeadlineExceeded:
+				ui.Error("Cancelling provisioner after a timeout...")
+			default:
+				// the context also gets cancelled when the provisioner is
+				// successful
+			}
+		}
+	}()
+
+	err := p.Provisioner.Provision(ctx, ui, comm)
+	close(errC)
+	return err
 }