[znpy]

> Tl;Dr is it a di*k move to ignore or reject pull requests that use non-English languages in commit msgs even though the project is all documented in English and is not a local project?

No.

> What do you think, and what is the professional approach to sth like this?

1. Be thankful to the person that made these commmits

2. Explain that comments in a language other than english are difficult for you to understand and will be difficult for other people to understand as well, in the future

3. Ask the person to re-submit the pull request with commit messages in english, warning that you'll have to reject the pull-request otherwise