I need to determine whether a given ELF file originated from Go. According to this link:
$ readelf -a traefik.stripped | grep "\.note\.go\.buildid"
Is this in any way inferior to go's native way:
$ go tool buildid traefik.stripped
oPIWoPjqt1P3rttpA3ee/ByNXPhvgS37nIoJY-HYB/8b25JYXrgktA-FYgU5MU/0Posfq41xZW9BEPEG4Ub
Are both methods guaranteed to work on stripped binaries?
I need to determine whether a given ELF file originated from Go
That is impossible to do in general. What is and isn't a Go binary is not well defined, and a sufficiently optimized Go binary may end up containing just a few instructions. E.g. on x86_64, you may end up with a single HLT instruction.
how come strip itself doesn't remove this section?
This section (indeed every section) is not necessary for execution -- you can remove all sections, and the binary will still work.
This section is present only to help developers identify a particular build. strip doesn't remove it by default because that would defeat the purpose of this section, but it certainly can do so.
can an innocent go developer build a golang ELF and accidentally remove this (redundant??) section
Sure. The developer can run a broken version of strip, or he can have aliased strip with strip --strip-all, or he could have used some other ELF post-processing tool, or he could have used UPX, or ...