Local does a pretty good job of scrubbing private info from the logs and the errors it produces, however there’s always the possibility that something private can come through. Because these are public forums, always review the screenshots you are sharing to make sure there isn’t private info like passwords being displayed.
We don’t compile GMP with our PHP versions - we use bcmath instead. Can you tell me more about how your site is using GMP? Is there a reason you need GMP and can’t leverage another math package like bcmath?
Those older instructions for enabling PHP extensions are outdated and probably don’t work. On the thread you linked - intl has been added to all of our PHP versions, but we should clean up the old post. Thanks for finding that!
Adding GMP though should be relatively straightforward - I can turn this into a feature request and ask the engineering team to take a look!