considering the choices "trivial", "minor", "major", "critical", "blocker", this seems to mix up priority and difficulty somehow.

for example, if there is a some severely wrong information somewhere in a docstring, what is this?

is it "trivial", because it is easily fixed in a minute?

is it "major", because one wants to fix such easy stuff with high priority (esp. as it takes about not time to get this off one's desk)?

so, i suggest to split this:

difficulty: low, medium, high

priority: low, medium, high

when considering this, one finds that even this might not be enough.

if some issue is a lot of work to fix, but easy work, just saying difficulty low is correct, but not enough.

So we get this:

difficulty: low, medium, high

effort: low, medium, high

priority: low, medium, high

(and of course there is always some "unknown/unspecified" choice also)