WITH_REPRODUCIBLE_BUILD revision 312730 
1$FreeBSD: stable/11/tools/build/options/WITH_REPRODUCIBLE_BUILD 312730 2017-01-25 01:04:51Z emaste $
2Set to exclude build metadata (such as the build time, user, or host)
3from the kernel, boot loaders, and uname output, so that builds produce
4bit-for-bit identical output.
5