[tor-bugs] #10304 [Tor]: libevent2 detection fails on FreeBSD 9.2

[Tor Bug Tracker & Wiki]

#10304: libevent2 detection fails on FreeBSD 9.2
-------------------------+-------------------------------------------------
     Reporter:  hsn      |      Owner:
         Type:  defect   |     Status:  needs_information
     Priority:  normal   |  Milestone:  Tor: 0.2.6.x-final
    Component:  Tor      |    Version:  Tor: unspecified
   Resolution:           |   Keywords:  tor-relay build 025-backport
Actual Points:           |  026-triaged-1
       Points:           |  Parent ID:
-------------------------+-------------------------------------------------

Comment (by nickm):

 Hm. So, Libevent ships with two headers called event.h.  One of them is
 the preferred Libevent 2 header, and goes somewhere where it can be
 included with "#include <event2/event.h>".  The other header exists for
 backward compatibility with Libevent 1, and you are supposed to be able to
 include it with "#include <event.h>".

 Because all Libevent versions install the "<event.h>" header, but only
 Libevent 2 installs the "<event2/event.h>" header, Tor searches for
 "<event.h>" in order to find out where the Libevent headers might be.

 But in FreeBSD 9.2, apparently, the compatibility headers are installed in
 a subdirectory called "compat", so searching for "<event.h>" won't find
 them.

 Here are our (non-exclusive) options as I see them:
   1. Let the FreeBSD ports maintainers continue to patch this situation in
 their Makefile. (Their nonstandard libevent installation: their problem.)
   2. Do a FreeBSD-specific workaround, where if we detect that you're
 running FreeBSD and you don't have a --with-libevent-dir option set,
 manually set the includes correctly.
   3. Tweak our search to look for event2/event.h in addition to event.h ,
 or to try adding foo/event2/compat to our search path whenever we're
 trying foo/. (This would require some tweaking in the middle of the
 hairiest bit of acinclude.m4.)
   4.  '''Finally''' start transitioning towards pkg-config. (Tweaking
 acinclude.m4 would also be required in this case too.)

 For 0.2.5, the easiest options seems like 1 or 2.  For 0.2.6 or maybe
 0.2.???, I think 4 is our best option, and 3 is best avoided.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/10304#comment:11>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online