As suggested in lib/33569, tech-userlevel may be a better place to
discuss this: are there any objections to exporting systrace.h to
userland? At least one useful application, sysjail[1], requires this
header file. I think it would be an asset if it can be installed
through pkgsrc or pkgsrc-wip in the future, without further tinkering
on the end-user side.

-- Daniel

[1] sysjail is a drop-in replacement for FreeBSD jail:
    http://sysjail.bsd.lv/