Commit to your team before you commit to git
If you say "I don't know", be sure to also say "but I'll find out".
In The Pragmatic Programmer, David Thomas and Andrew Hunt write: “When you find yourself saying ‘I don’t know’, be sure to follow it up with ‘but I’ll find out’. It’s a great way to admit what you don’t know, but then take responsibility like a pro”.
I agree with them.
When writing software, we are first and foremost trying to solve real problems for real people. We must be committed to helping people using computers as a tool. In doing so, we must also avoid creating more problems!
We can never know everything, and we cannot anticipate all problems that might come ahead, so it is perfectly reasonable in my opinion to say “I don’t know”. But, when we are committed to the people, we commit to the solution of their problems, and that will naturally make us say “but I will find out”.