• (REW) Sometimes bad hardware causes this. Read the Web page at http://www.BitWizard.nl/sig11/ about this. The important word here is random. If it stops at the same place every time, the kernel source might have a glitch or your compiler might be bad. The Web page is mostly about the random error source: hardware. There is a bunch of different error messages that you can get if you have bad or marginal hardware. • (ADB) Overclocked processors very often fail long compilations with a sig11, because a long gcc compilation puts more strain on the processor. As the processor heats up, it may attain a point where internal timings get out of spec. At this point, something gives and you get a sig11. Also, some old K6 revisions would sig11 when compiling large programs if > 32 Mb of RAM were installed on the Linux box. AMD will exchange these faulty processors for free. Benoit Poulot-Cazajous correctly diagnosed the problem and devised an ingenious test for this bug that is run at boot time