Yes the initial patch was: https://people.freebsd.org/~bapt/reproduciblebuild.diff
I decided in the version to drop the default TIMESTAMP as it can generate failures on packages, and prefer to only have reproducibility on packages having a timestamp (most of them should have now)
I was wondering about ports without a distinfo file (like, say, ports-mgmt/portlint) but they could gain a distinfo file with only a TIMESTAMP in it.
Maybe this should be in a .else for the next .if.
Can you cache this using the usual mechanism so that we do not run awk in each submake?