-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello Ximin, can you strace ?
On 07/12/16 00:27, Ximin Luo wrote: > Ximin Luo: >> Ximin Luo: >>> Bill Allombert: >>>> On Tue, Dec 06, 2016 at 01:01:00PM +0000, Ximin Luo wrote: >>>>> Bill Allombert: >>>>> Hi all, >>>>> >>>>> Sorry I only just briefly scanned through the thread now. However I >>>>> found this post relating to gzip, pipes and python: >>>>> >>>>> https://blog.nelhage.com/2010/02/a-very-subtle-bug/ >>>>> >>>>> which summarises the bug report here: https://bugs.python.org/issue1652 >>>> >>>> Yes, this is exactly the problem, and it seems it has been fixed in python >>>> 3, >>>> but not in python 2.7. >>>> >>> >>> Ok, good to know! The blog post also contains a work-around near the end, >>> which is to add >>> >>> preexec_fn=lambda: signal.signal(signal.SIGPIPE, signal.SIG_DFL) >>> >>> as a parameter to the relevant Popen call. Presumably in this case it's >>> wherever Sage calls GAP. Jerome, could you test? >>> >> >> Hi Bill, >> >> I'm not sure if the above bug is the cause of this issue. I tried to >> reproduce it without Sage: >> >> $ apt-cache policy gap >> gap: >> Installed: 4r8p6-1 >> Candidate: 4r8p6-1+sage17 >> Version table: >> 4r8p6-1+sage17 500 >> 500 https://debian-science.alioth.debian.org/apt sid-sage/ Packages >> *** 4r8p6-1 500 >> 500 http://httpredir.debian.org/debian testing/main amd64 Packages >> 500 http://httpredir.debian.org/debian unstable/main amd64 Packages >> 100 /var/lib/dpkg/status >> >> $ python -c 'import subprocess; subprocess.Popen(["gap", "-q"], >> stdin=subprocess.PIPE).communicate("?SymmetricGroup")' >> >> gzip: stdout: Broken pipe >> Help: several entries match this topic - type ?2 to get match [2] >> >> [1] Reference: SymmetricGroup >> [2] Reference: SymmetricGroup (for a degree) >> [3] Reference: SymmetricGroup (for a domain) >> >> $ python -c 'import signal, subprocess; subprocess.Popen(["gap", "-q"], >> stdin=subprocess.PIPE, preexec_fn=lambda: signal.signal(signal.SIGPIPE, >> signal.SIG_DFL)).communicate("?SymmetricGroup")' >> Help: several entries match this topic - type ?2 to get match [2] >> >> [1] Reference: SymmetricGroup >> [2] Reference: SymmetricGroup (for a degree) >> [3] Reference: SymmetricGroup (for a domain) >> >> So as you can see, the bug is only to do with the extra "Broken pipe" error >> messages. > > And in fact, if I patch src/sysfiles.c to say "gzip 2>/dev/null -cd " instead > of "gunzip " then the "Broken pipe" messages go away. > > The below Sage/GAP error still occurs, though: > >> However Sage fails in a different way: >> >> $ ./sage -c 'gap.help('SymmetricGroup', pager=False)' >>> /usr/lib/python2.7/dist-packages/ptyprocess/ptyprocess.py(220)spawn() >> -> if use_native_pty_fork: >> (Pdb) c >>> /usr/lib/python2.7/dist-packages/ptyprocess/ptyprocess.py(220)spawn() >> -> if use_native_pty_fork: >> (Pdb) c >> #W corrupted 'manual.six': ##W (in stream: >> InputTextFile(/usr/share/gap/doc/t\ >> ut/manual.six)) >> #W corrupted 'manual.six': ##W (in stream: >> InputTextFile(/usr/share/gap/doc/c\ >> hanges/manual.six)) >> #W corrupted 'manual.six': ##W (in stream: >> InputTextFile(/usr/share/gap/pkg/G\ >> APDoc/example/manual.six)) >> Help: no matching entry found >> > - -- Jerome BENOIT | calculus+at-rezozer^dot*net https://qa.debian.org/developer.php?login=calcu...@rezozer.net AE28 AE15 710D FF1D 87E5 A762 3F92 19A6 7F36 C68B -----BEGIN PGP SIGNATURE----- iQQcBAEBCgAGBQJYR2F/AAoJED+SGaZ/NsaLmsgf/iApRccFu1xSil7p7Pu2y2Ed gYlaXzqYhMjELbKYb2dWok8NRO84NeOAK62YX9K2mb28MUsXgBXzC1XHzXT8SVJy Y3EwvvmlpZE7Pr6ULavAXud/lL65u+3VPP+rv+e4esdEnE0DfQmoAAhi6t+oRPsU M36ksqPUPTsLcVf2ITjI5rha6FF5urMf4Ng+0kmZwrc4w/B5EdntOyXySE5fS8/e 731/NCICLL3ab5FbN7pGenQqIKOKTXMmadNoLehYrHFyg7SOw17eoub/FiM6e5aq 2ubCfCBR07KEZm2t4ooKp1Pu8lpJhx/K3TqWHAmI7QtjDh7UPUkwBfGVc8YfW+/y X753F6X+LhlEkz9TZ9v3bk6hjG1TLQzXJ1ui8oBf9oAQxDZFnUvd53L/MwNtNPG9 fIHcgwnbQPZ8MQyi8JOMgaUvGS5aB5jhS5I0y2UivNtXn+xjRx3A8mjkJrcKRWn+ +BWTlT0F9xBtJBtnCHd6DAtEWdaYZr+8wMyiT8Cm2ifb5WrmMHwbbFjvyQ6+qLLh i78kZDu9LwT1KZzj00BgqpJnWaJtfZDGrnLUJh3d0q2+wsxNfV3lRRwHMn0zDiH1 KO/zCILK2GP6a1bf/LG4g9uVkqm/KBsvUunv0guI4KCiQ7WmVbffwX8YX7mYyCdE bpyxmKyryfYiXk4L5iI7FoGPsHLYqpWIo+qW0mYz2hW9oliwDzLO6TAR4F1tsXKr tfAIXKohH9W2ntvRRavrLSP+VwwNPPiIg5no15Vuyc4ugIwMl0/hAubkCOMyKTQk I6d7gVr3hw9BR5OOmRaqwpvqgbgqfGwVIxGB8e1+e18FzGKNqcVDa/e9k2HtbquY xyPLXQe6W9OTvhtdxV3UQHZv5Bd9JT0D3jPEvAIvjrUzRv2DqrRkY2PHwuq5K3TR AujF1miEcCrV8by46A5Wqv0hneRSfeVicR0n7fxqdxbSFgQvSEu9FvjUvuXZHf7P KyU1n3aoyka+/ZuVlyp7RStKXTShmDN9rY3j5Yw/S3AkC09PBoHcf45t8pixHdFc pqGW+qMeyLfJw9hllumMwGm85ZUDZMJfZzJOMcliUy5vMAKeboGJIILP0996J9G0 r/tsh6Fa55b3Pau19WpWOURiiQqw5T5h1Y8Dmkjg7XQyC744EkgH0onjDqEtxYgX IU5ALHNfXj76x+Y0VXl2qCzEblZx+9Q6+nmeE+PIRcU5PX/+TeCaIoLhM3TyV1D1 3eIGWxtSXFq7MV40RNcLViZO7JtDAWnHzRmilEM4X8pvzdVIZwrHcOqLgC2S0lMh vEQQz/SIepfYvJyg3b7VrWoXJrjSU37fEfhL2ySEzWcA2coTa9FSDgtR4cZpSGo= =bdPo -----END PGP SIGNATURE-----
