New comment by therealfun on mblaze repository

https://github.com/leahneukirchen/mblaze/pull/201#issuecomment-773480308

Comment:
> I need to think about whether this is a good semantics change.

It was surprising for me to find that `magrep -v header:pattern` doesn't match messages if that header is missing. If this was your intention, maybe you should leave it as it is.
I see that I have at least two methods for my use-case :)