[RFC] Use of the Nacked-by tag by CI scripts

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Hi,

The Nacked-by tag can be used to manually hold a patch for further 
review, or by automatic CI because of failing test.

We often miss travis-ci and shippable failures. These CI provide a easy 
way to send email on failure, we can integrate the Nacked-by use there.

We can easily have patchew script send a Nacked-by tag.

If there is a consensus about using this tag, the following patch can be 
added to Peter's management scripts:
https://git.linaro.org/people/pmaydell/misc-scripts.git/

If we move to another workflow, having this uniform tag can help future 
merging scripts to avoid patch on hold to get automatically merged.

-- >8 --
Subject: make-pullreq: Do not automatically merge NAcked commits

The 'Nacked-by' tag is a polite way of holding a patch for
further review. Reviewers might share their disapproval with
it (see [1]).

CI scripts might NAck a patch if it breaks testing.
QEMU already thought about using this tag for CI by the past
(see [2]).

The patchwork tool already collects this tag (see [3]).

Also, there was a discussion at the last Open Source Summit
about standardizing it ([4]).

Maintainers might miss a such Nacked-by tag. Help them by
providing a last resort check before merging pull requests.

[1] 
https://www.x.org/wiki/Development/Documentation/SubmittingPatches/#index1h1
[2] https://lists.gnu.org/archive/html/qemu-devel/2013-01/msg00196.html
[3] 
http://git.ozlabs.org/?p=patchwork;a=blobdiff;f=apps/patchwork/models.py;h=fa213dc03e;hp=8871df0259e;hb=487b53576f;hpb=a59ebf107d84b
[4] 
https://lore.kernel.org/workflows/CACT4Y+bxPxQ64HEO2uGRkbk9vJSeg64y10Lak4c2K54J7GyFFA@mail.gmail.com/

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
  make-pullreq | 11 +++++++++++
  1 file changed, 11 insertions(+)

diff --git a/make-pullreq b/make-pullreq
index 61c0f1d..fff0b2d 100755
--- a/make-pullreq
+++ b/make-pullreq
@@ -108,6 +108,17 @@ if [ "$bad" = "yes" ]; then
     exit 1
  fi

+# Check no commit contains a nacked-by tag
+for rev in $(git rev-list master..HEAD); do
+    if git log ${rev}^! | grep -iq "Nacked-by:"; then
+        echo "Error: commit ${rev} nacked"
+        bad=yes
+    fi
+done
+if [ "$bad" = "yes" ]; then
+   exit 1
+fi
+
  # Check whether any authors needs to be corrected after SPF rewrites
  if git shortlog --author=qemu-devel@nongnu.org master..HEAD | grep .; then
      echo "ERROR: pull request includes commits attributed to list"
-- 
2.21.0