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I routinely use a virtual gentoo ~amd64 machine in VirtualBox for |
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debugging software problems and yesterday I found one after switching |
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from gcc-4.9.3 to gcc-5.3.0 (in the gentoo guest). |
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After emerging mesa-11.1.2-r1 I noticed that a game wouldn't start, and |
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after several hours of debugging I tracked it down to gcc5. |
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To demonstrate the bug, in an xterm window type "glxinfo": |
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# glxinfo |
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name of display: :0.0 |
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libGL error: unable to load driver: swrast_dri.so |
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libGL error: failed to load driver: swrast |
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X Error of failed request: GLXBadContext |
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Major opcode of failed request: 153 (GLX) |
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Minor opcode of failed request: 6 (X_GLXIsDirect) |
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Serial number of failed request: 48 |
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Current serial number in output stream: 47 |
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I could 'fix' the bug by replacing just that one file (swrast_dri.so) |
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with a copy compiled with gcc-4.9.3. I'm surprised it worked, but it |
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did. |
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I tried building mesa using gcc5 on a real ~amd64 machine and did *not* |
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see the same problem, FWIW, but though I'd mention it here. |
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BTW I tried building the vbox guest additions with gcc5 as a test but |
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that didn't fix the problem. I don't have a real machine that's built |
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entirely with gcc5 so I can't test that idea yet, and that won't be any |
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time soon. I'm sticking to gcc4 for the foreseeable future while you |
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guys do more testing :) |