> To infer the triplet, we can search for "CONFIG_ARM64=y".

Not really, it's not in the u-boot tarball before it started building it.  Hmm...

But you're right, it shouldn't be cross-compiling it in the first place if "-s"
works (or if the user builds it on the target anyway), so we could just punt on
this entirely.

P.S. how do I make make-u-boot-package default triplet to the host triplet?
(%current-system) is not a gnu triplet, right?