Why does `make engine:lint` complain on

[desert isle]

Sorry I lost track of this until I saw your comment on the docs PR, I believe this is because golangci-lint automatically skips anything under testdata by default. golangci-lint run --help shows that --skip-dirs-use-default is set to true by default and results in testdata being skipped (among some others)

[patent monolith]

I thought it could be something like that but:

• I didn't see anything pointing to that in .golangci.yml;
• testdata is being added in RepositoryGoCodeOnly;
• There's no other option being passed to golangci-lint;

So thanks 🙏, that answers the question (it's a default):

run:
  # Enables skipping of directories:
  # - vendor$, third_party$, testdata$, examples$, Godeps$, builtin$
  # Default: true
  skip-dirs-use-default: false