Utility pstree(1) from sysutils/psmisc expects "linux content" in /proc. In FreeBSD ports this is solved by files/patch-src-pstree.c to teach pstree(1) to read also other types of /proc. Unfortunately, ifdefs in that patch cover just FreeBSD. On DragonFly "the linux code" is compiled and pstree then just says "/proc is empty (not mounted ?)".
Utility pstree(1) from sysutils/psmisc expects "linux content" in /proc. In FreeBSD ports this is solved by files/patch-src-pstree.c to teach pstree(1) to read also other types of /proc. Unfortunately, ifdefs in that patch cover just FreeBSD. On DragonFly "the linux code" is compiled and pstree then just says "/proc is empty (not mounted ?)".
Solution is to enlarge those ifdefs:
-#ifdef FreeBSD +#if defined(FreeBSD) || defined(DragonFly)
I've verified this is sufficient to make pstree(1) work also on DragonFly.
Note: it'd be best to change this directly in FreeBSD ports, but it's DragonFly issue, so I'm reporting here.