xdelta3 is needed by app-emulation/xtrs for binary patching. I've tested on FreeBSD: It builds without problems, and xdelta3's output files are identical to the ones it produces on Linux, both for compressing and uncompressing.
Tested on amd64-fbsd too, seems to work fine there.
Added ~x86-fbsd.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=310173a91b2b19c03064fdd0ebd8bf2fed51e0da commit 310173a91b2b19c03064fdd0ebd8bf2fed51e0da Author: Patrice Clement <monsieurp@gentoo.org> AuthorDate: 2017-11-18 22:58:17 +0000 Commit: Patrice Clement <monsieurp@gentoo.org> CommitDate: 2017-11-18 22:58:17 +0000 dev-util/xdelta: keyword for amd64-fbsd. Closes: https://bugs.gentoo.org/507562 Package-Manager: Portage-2.3.13, Repoman-2.3.4 dev-util/xdelta/xdelta-3.0.11.ebuild | 2 +- dev-util/xdelta/xdelta-3.1.0.ebuild | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)