I wonder if the sentence "This pull request and merge is a mess" has a correct grammar.
"pull request and merge" are two words so the verb should possibly be in plural for "This pull request and merge are a mess"? Furthermore, "These pull request and merge is/are a mess" sounds wrong in my ear. "These pull requests and merges are a mess" is not what I meant (there is only on pull request and one merge). Perhaps "pull request and merge" should be regarded as some form of collective?
A rephrased sentence seems grammatical to me: "This pull request with a merge is a mess".
I note a similar question Plural of noun and concept takes singular verb?