This happened in https://github.com/openjdk/jdk/pull/20781. One of the original commits that imported 3rd party source code contained a lot (I mean a lot) of trailing white spaces. This made jcheck produce a huge response, which it then failed to post to Github:

{"message":"Invalid request.\n\nOnly 65535 characters are allowed; 136719 were supplied.","documentation_url":"https://docs.github.com/rest/checks/runs#create-a-check-run","status":"422"}

There are many ways we can address this. One is to limit what we try to post as a check result to Github. But even 64 kB is too large; if we got to that point, it will not be helpful. So I propose that we instead (or also?) add an error limit to jcheck. Maybe set it at 100; I think this is what javac has as default. In fact, it could probably be 10 as well as far as the Github check goes, but perhaps with the use case of someone running jcheck locally to find and fix all errors, this might be too low.

Also, when the limit gets hit, jcheck must omit a final error saying that the limit got hit, so this is clear.