I encountered a single occurrence of this while building core-updates (2073b55e6b964cb8ca15e8c74cb32dac00f05f0d). I couldn't reproduce the hang a 2nd time, but in case it'd occur to someone else, I'm reporting the problem here.
The build appears to be hung, peeking a single CPU core with no output. The last output printed is: --8<---------------cut here---------------start------------->8--- Executing "/tmp/guix-build-fftw-3.3.8.drv-0/fftw-3.3.8/tests/bench -o nthreads=2 --verbose=1 --verify 'ofr39v157' --verify 'ifr39v157' --verify '//obc39v157' --verify '//ibc39v157' --verify '//ofc39v157' --verify '//ifc39v157' --verify 'obc39v157' --verify 'ibc39v157' --verify 'ofc39v157' --verify 'ifc39v157' --verify 'ok7e00x27o11v28' --verify 'ik7e00x27o11v28' --verify '//obr23232' --verify '//ibr23232' --verify '//ofr23232' --verify '//ifr23232' --verify 'obr23232' --verify 'ibr23232' --verify 'ofr23232' --verify 'ifr23232' --verify '//obc23232' --verify '//ibc23232' --verify '//ofc23232' --verify '//ifc23232' --verify 'obc23232' --verify 'ibc23232' --verify 'ofc23232' --verify 'ifc23232' --verify 'ok11e11x6bv16' --verify 'ik11e11x6bv16' --verify 'obr3x6v25' --verify 'ibr3x6v25' --verify 'ofr3x6v25' --verify 'ifr3x6v25' --verify '//obc3x6v25' --verify '//ibc3x6v25' --verify '//ofc3x6v25' --verify '//ifc3x6v25' --verify 'obc3x6v25' --verify 'ibc3x6v25' --verify 'ofc3x6v25' --verify 'ifc3x6v25' --verify 'ok10bx8e10x7bx5o01*8' --verify 'ik10bx8e10x7bx5o01*8'" ofr39v157 3.88346e-16 2.86256e-16 7.57002e-16 ifr39v157 3.47982e-16 2.86256e-16 7.02064e-16 //obc39v157 3.94083e-16 5.72513e-16 8.78504e-16 //ibc39v157 4.03859e-16 4.29385e-16 9.40757e-16 //ofc39v157 4.42394e-16 4.29385e-16 8.87713e-16 //ifc39v157 4.12348e-16 4.29385e-16 8.5851e-16 obc39v157 4.0602e-16 4.29385e-16 8.48734e-16 ibc39v157 3.73274e-16 4.29385e-16 8.9751e-16 ofc39v157 3.97926e-16 4.29385e-16 8.07659e-16 ifc39v157 4.07119e-16 4.29385e-16 7.61853e-16 ok7e00x27o11v28 3.41262e-16 4.83151e-15 3.96424e-16 ik7e00x27o11v28 3.94159e-16 4.37137e-15 3.94158e-16 --8<---------------cut here---------------end--------------->8--- The 'bench' program is the one responsible for such a long execution/hang. The build of fftw had been ongoing for about 500 CPU minutes. It may be related to the tests using more than one thread (some deadlock perhaps). Maxim
