Hey there!

Several Linux distros (at least Arch, Debian and SUSE) are striving for reproducible builds, as a way to verify build systems and guarantee the legitimacy of build servers and whatnot. The build time injection done in the Makefile makes building fscrypt an unreproducible process.

The Arch Linux PKGBUILD already applies a patch to the Makefile to make it reproducible, and on Debian it's flagged as unreproducible. Fixing this issue upstream is probably the best way of widely making fscrypt a reproducible build.