I'm uncomfortable with including something that only works on certain versions of a single platform. Are there any other functions or methods (not modules) that are only available for Linux? I can think of a number of places flagged as "Availability: Unix", but if getpeercred() doesn't work on the BSDs, it doesn't even meet that standard.

If a decision is made to include this, and if it only works on Linux 2.4+, I'd rather see it not available at all on other platforms (rather than returning dummy values).