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kgizdov

Package Maintainer (PM)

From: Edinburgh, UK

Registered: 2015-12-08

Posts: 113

[SOLVED] X Forwarding on Xeon box with MGA VGA

Hi,

Not sure if this is the correct section, so let me know if that's the case.

I am having the weirdest problem with X forwarding. I have a dedicated server with dual Xeon E5504 and an MGA G200eW WPCM450 VGA. I am trying to set it up for a small compute node. I have installed and configured mesa, mga-dri, ssh, Xorg, X Forwarding, etc. and confirmed it works with xeyes.

My problem is the following. I am trying to use an analysis framework - CERN's ROOT with the package root-extra from AUR (I am the package maintainer). When I launch the framework, I am able to see the splash screen correctly forwarded and all works. However, when I try to load a more complex GUI element, like a data browser, the framework crashes with:

Generating stack trace...
 0x00007fbadca4255d in cling::Interpreter::EvaluateInternal(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, cling::CompilationOptions, cling::Value*, cling::Transaction**, unsigned long) + 0x18d from /usr/lib/root/libCling.so
 0x00007fbadca4262c in cling::Interpreter::evaluate(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, cling::Value&) + 0x1c from /usr/lib/root/libCling.so
 0x00007fbadc9b8ffe in TCling::Calc(char const*, TInterpreter::EErrorCode*) + 0xce from /usr/lib/root/libCling.so
 0x00007fbae0fd60d6 in TROOT::ProcessLineFast(char const*, int*) + 0x86 from /usr/lib/root/libCore.so
 0x00007fbad1ea3683 in <unknown> from /usr/lib/root/libGX11.so
 0x00007fbad1b986fd in _XError + 0x11d from /usr/lib/libX11.so.6
 0x00007fbad1b95627 in <unknown> from /usr/lib/libX11.so.6
 0x00007fbad1b956e5 in <unknown> from /usr/lib/libX11.so.6
 0x00007fbad1b965f8 in _XReply + 0x238 from /usr/lib/libX11.so.6
 0x00007fbad1b812ff in XInternAtom + 0xcf from /usr/lib/libX11.so.6
 0x00007fbad0d07cfa in TGClient::TGClient(char const*) + 0x26a from /usr/lib/root/libGui.so
 0x00007fbad0dee793 in TRootApplication::TRootApplication(char const*, int*, char**) + 0x83 from /usr/lib/root/libGui.so
 0x00007fbad0e11ab1 in TRootGuiFactory::CreateApplicationImp(char const*, int*, char**) + 0x31 from /usr/lib/root/libGui.so
 0x00007fbae104934a in TApplication::InitializeGraphics() + 0x17a from /usr/lib/root/libCore.so
 0x00007fbae10533bd in TBrowser::TBrowser(char const*, char const*, TBrowserImp*, char const*) + 0x8d from /usr/lib/root/libCore.so
 0x00007fbae18ab0be in <unknown function>
 0x00007fbadca912d8 in cling::IncrementalExecutor::runStaticInitializersOnce(cling::Transaction const&) + 0x328 from /usr/lib/root/libCling.so
 0x00007fbadca43593 in cling::Interpreter::executeTransaction(cling::Transaction&) + 0x73 from /usr/lib/root/libCling.so
 0x00007fbadca997a3 in cling::IncrementalParser::commitTransaction(llvm::PointerIntPair<cling::Transaction*, 2u, cling::IncrementalParser::EParseResult, llvm::PointerLikeTypeTraits<cling::Transaction*>, llvm::PointerIntPairInfo<cling::Transaction*, 2u, llvm::PointerLikeTypeTraits<cling::Transaction*> > >&) + 0x4a3 from /usr/lib/root/libCling.so
 0x00007fbadca9cd26 in cling::IncrementalParser::Compile(llvm::StringRef, cling::CompilationOptions const&) + 0x66 from /usr/lib/root/libCling.so
 0x00007fbadca4245e in cling::Interpreter::EvaluateInternal(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, cling::CompilationOptions, cling::Value*, cling::Transaction**, unsigned long) + 0x8e from /usr/lib/root/libCling.so
...

Seems like an X API mismatch, but I'm not sure. I have tried all I know to correct this. I installed Xorg devel, utils, etc., made sure everything is linking correctly at compilation and recompiled several times. `ldd` does not complain and all the relevant lib files are there. I have previously setup the same X Forwarding from my desk machine at home, which has NVidia VGA, and all this works fine. The main difference I see here is that the desk machine has GDM and GNOME and the server does not have a display manager. I do not think that is necessary. Am I wrong?

Is this an X Forwarding issue? Is it a driver issue? Is it that ROOT wants an API the MGA driver doesn't have? I am really out of my depth here. Anyone has any ideas on how to debug this?

Thanks.

EDIT:
Bug was fixed upstream. For other people's future reference - ROOT also requires trusted forwarding to function properly.

Last edited by kgizdov (2017-02-24 14:43:10)