PUFFY (Pledge & Unveil Facilitated For You) wraps Go’s Pledge,
PledgePromises, PledgeExecPromises, Unveil, and UnveilBlock functions,
making them available on platforms other than OpenBSD. Rather than cause your
build to fail, on those platforms they will simply be no-ops.
This relieves you from having to write OS-specific files each time you want to
use pledge or unveil in a Go project—PUFFY does the work for you.