Fix OpenBSD build bot errors

The OpenBSD build bot shows a lot of errors like https://buildbot.pixelminers.net/builders/OpenBSD/builds/1051 (Needs a non-HSTS browser, the cert has expired.)

There are a few warnings, some GCC pragmas that don't work, and evdns isn't linking correctly. So that might require help from the admin.

changed milestone to %Tor: 0.2.9.x-final

added TorCoreTeam201611 build component::core tor/tor milestone::Tor: 0.2.9.x-final openbsd points::0.5 priority::medium resolution::fixed severity::normal status::closed type::defect labels

The libevent2 problem is that commit 265e40b481d23ea0ee8b4e1705fb013532d1f6b2 removed a check for the headers, and there's a conditional that relies on the result of that check, so that conditional always fails and configure falls back to linking libevent2 with -levent, it just happens that this works on every platform that isn't OpenBSD (the whole conditional path that gets skipped was added specifically for OpenBSD in the first place).

Since libevent2 is mandatory now I think it makes sense to add the header check back in and change the fall back path to an error.

This patch gets tor successfully building HEAD (5e571900b341b) on OpenBSD -current amd64

Trac:
Username: rubiate

Trac:
Username: rubiate

tor2.patch

Readd check for libevent2 headers to fix build on OpenBSD, and change the fallback path to an error

Trac:
Username: rubiate

Trac:
Username: rubiate
Cc: N/A to cb@viennan.net

Does some branch of Tor not build on openbsd right now? If so, should we file specific tickets about the issue(s), in the right branches?

On the latest released OpenBSD (6.0), Tor builds on at least the latest of 0.2.{7,8,9} and 0.3.0. The libevent problem was fixed (again!) in #19902 (moved).

There are a few warnings but I think they're all just the ancient GCC OpenBSD uses getting confused, and there's probably no way to deal with them, ie. the pragmas not working to silence the overlong string warnings.

There's one test (util/time) that fails on 6.0 but passes on 6.0-current -- the problem was a bug in OpenBSD libc, and the OpenBSD devs didn't think it was worth backporting the fix to 6.0-stable, so I don't know if that matters.

So everything is mostly fine on the OpenBSD front at the moment.

Trac:
Username: rubiate

Ok. I will leave it to teor (the original reporter) to close this ticket, or do something else if he desires.

I'm going to call this fixed in 0.2.9, please open a separate ticket for any further issues.

Trac:
Keywords: N/A deleted, openbsd, build, TorCoreTeam201611 added
Status: new to closed
Milestone: Tor: 0.2.??? to Tor: 0.2.9.x-final
Resolution: N/A to fixed

closed

changed time estimate to 4h

mentioned in issue #19902 (moved)

moved to tpo/core/tor#19758 (closed)