megaglest cannot host game or connect to LAN game

[Mark Abrahams]

On Ubuntu 16.10, when I click "Find LAN games" I get a stack trace error message on the screen.

This appears in the log ~/.megaglest/error.log:

[2016-11-05 19:45:26] Runtime Error information:
======================================================
In [/build/megaglest-7_VKRd/megaglest-3.12.0/source/glest_game/main/main.cpp::handleSIGSEGV Line: 5862] Error detected: signal 11:

Stack Trace:
megaglest:Glest::Game::ExceptionHandler::handleRuntimeError(char const*, bool)address [0x55b1988dd2c9] line: 0
megaglest:()address [0x55b1988dd835] line: 0
/lib/x86_64-linux-gnu/libc.so.6:()address [0x7fee776ef860] line: 0
megaglest:Glest::Game::MenuStateJoinGame::DiscoveredServers(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std
::char_traits<char>, std::allocator<char> > > >)address [0x55b1989c0629] line: 0
megaglest:Shared::Platform::BroadCastClientSocketThread::execute()address [0x55b198d2e2c5] line: 0
megaglest:Shared::Platform::Thread::beginExecution(void*)address [0x55b198cf55c5] line: 0
/usr/lib/x86_64-linux-gnu/libSDL2-2.0.so.0:()address [0x7fee7a8da1ec] line: 0
/usr/lib/x86_64-linux-gnu/libSDL2-2.0.so.0:()address [0x7fee7a929629] line: 0
/lib/x86_64-linux-gnu/libpthread.so.0:()address [0x7fee7a64870a] line: 0
/lib/x86_64-linux-gnu/libc.so.6:clone()address [0x7fee777c20af] line: 0

Possibly related is the when I try to host a game I get "LAN IP Address(es):none" showing at the top of the screen, and no other LAN megaglest client can connect to my hosted game.

[Tom Reynolds (tomreyn)]

Hi Mark, does your network offer IPv4 addressing, or just IPv6?
MegaGlest does not support IPv6 at this time.

[Mark Abrahams (mark-abrahams)]

Hi Tom - my network has dual IPv4 and IPv6 addressing, and IPv4 networking in general was working (I could ping other LAN hosts). I noticed a megaglest strace doing an AF_INET6 bind at some point, so I turned IPv6 off the interface - leaving it IPv4 only - to eliminate any potential problems with IPv6. Still got the same error though.

I downloaded the 3.12.0 version from megaglest.org onto the same machine, and with this version LAN games - both hosting and connecting to a hosted game - worked fine.

I should also note that three other Ubuntu 16.10 machines running Megaglest run fine without this error. I'm trying to determine what is a significant difference with the problem machine.

[Tom Reynolds (tomreyn)]

Thanks, Mark.

I did some testing but have been unable to reproduce the segmentation fault as of yet. I did succeed in reproducing the part where no LAN IP address is detected / shown by MegaGlest - using Ubuntu 16.10 x86_64 in a Virtualbox VM with either the Ubuntu package or our own ("upstream") releases.

I filed this bug on our own bug tracker about it:
https://github.com/MegaGlest/megaglest-source/issues/137

If you could provide steps to reproduce it reliably, this would be very helpful (but I understand it's not easy).

[Mark Abrahams (mark-abrahams)]

Hi Tom

The Ubuntu 16.10 package produces the error for me, but on only 1 out of
4 Ubuntu 16.10 machines, so there appears to be something
environmentally different with the problem machine. Also, the
downloaded version directly from megaglest.org works fine on the same
problem machine. It still does show "none" for the IP address, despite
the fact that it hosts a LAN game fine.

I'll try to find more information on reproducing the error, and will
post if I find something that might be useful. Thanks for your time on
this.

Regards, Mark.

On 13/11/16 05:06, Tom Reynolds wrote:
> Thanks, Mark.
>
> I did some testing but have been unable to reproduce the segmentation
> fault as of yet. I did succeed in reproducing the part where no LAN IP
> address is detected / shown by MegaGlest - using Ubuntu 16.10 x86_64 in
> a Virtualbox VM with either the Ubuntu package or our own ("upstream")
> releases.
>
> I filed this bug on our own bug tracker about it:
> https://github.com/MegaGlest/megaglest-source/issues/137
>
> If you could provide steps to reproduce it reliably, this would be very
> helpful (but I understand it's not easy).
>
> ** Bug watch added: github.com/MegaGlest/megaglest-source/issues #137
> https://github.com/MegaGlest/megaglest-source/issues/137
>

[SoftCoder (mark-vejvoda)]

Working on a fix for this should be pushed into git tonight

[SoftCoder (mark-vejvoda)]

Looks like this is already fixed in the latest git code, please retest.