Comment 1 for bug 1888659

Merge proposal diffs are the result of performing a trial merge into the tip of the target branch, so they can contain conflicts if the source and target branches have diverged. In general the fix is for the author of the source branch to merge or rebase onto the current tip of the target branch and resolve conflicts, which they seem to have done in this case.

Here's a script that reproduces the same conflicts locally based on the merge proposal you referenced:

  $ git clone lp:charm-prometheus-grok-exporter
  Cloning into 'charm-prometheus-grok-exporter'...
  [...]
  $ cd charm-prometheus-grok-exporter
  $ git remote add -f peppepetra86 lp:~peppepetra86/charm-prometheus-grok-exporter
  Updating peppepetra86
  [...]
  $ git checkout c9ef6f30b972b2d8996925a7b6cdd1fab9174ecb
  Note: switching to 'c9ef6f30b972b2d8996925a7b6cdd1fab9174ecb'.
  $ git merge 4f406206718135b8757289e43a4fe2f90f8d2736
  Auto-merging files/metrics-mapping.yaml
  Auto-merging files/grafana-dashboards/grok-exporter-dashboard.json
  CONFLICT (content): Merge conflict in files/grafana-dashboards/grok-exporter-dashboard.json
  Automatic merge failed; fix conflicts and then commit the result.
  $ git diff