Crash in flint/nmod_poly_linkage.pxi doctest

[rwst]

Sporadically on OpenSuSE make ptestlong crashes in libs/flint/nmod_poly_linkage.pxi:

sage: n = 2^23 ## line 518 ##
sage: alarm(0.2); x^n; cancel_alarm() ## line 519 ##
------------------------------------------------------------------------
/home/ralf/sage/local/lib/python2.7/site-packages/cysignals/signals.so(+0x7124)[0x7f127a105124]
/home/ralf/sage/local/lib/python2.7/site-packages/cysignals/signals.so(+0xb338)[0x7f127a109338]
/home/ralf/sage/local/lib/python2.7/site-packages/cysignals/signals.so(+0xb215)[0x7f127a109215]
/lib64/libpthread.so.0(+0x10c10)[0x7f127fc0ac10]
/lib64/libc.so.6(+0xf938b)[0x7f127f24a38b]
/lib64/libc.so.6(+0x7c046)[0x7f127f1cd046]
/home/ralf/sage/local/lib/python2.7/site-packages/cysignals/signals.so(+0x6e8f)[0x7f127a104e8f]
/home/ralf/sage/local/lib/python2.7/site-packages/cysignals/signals.so(+0x7850)[0x7f127a105850]
/home/ralf/sage/local/lib/python2.7/site-packages/cysignals/signals.so(+0xb111)[0x7f127a109111]
/lib64/libpthread.so.0(+0x10c10)[0x7f127fc0ac10]
/lib64/libc.so.6(+0x86a50)[0x7f127f1d7a50]
/lib64/libc.so.6(+0x7baaa)[0x7f127f1ccaaa]
/lib64/libc.so.6(+0x7c068)[0x7f127f1cd068]
/home/ralf/sage/local/lib/libflint.so.13(flint_malloc+0x6)[0x7f126ecd4bf6]
/home/ralf/sage/local/lib/libflint.so.13(_nmod_poly_mul_KS4+0x1f9)[0x7f126ed77239]
/home/ralf/sage/local/lib/libflint.so.13(_nmod_poly_mul+0x91)[0x7f126eda1d71]
/home/ralf/sage/local/lib/libflint.so.13(_nmod_poly_pow_binexp+0x165)[0x7f126ed86a95]
/home/ralf/sage/local/lib/libflint.so.13(nmod_poly_pow+0x7a)[0x7f126ed70eaa]
/home/ralf/sage/local/lib/python2.7/site-packages/sage/rings/polynomial/polynomial_zmod_flint.so(+0x1ad0a)[0x7f1202c0ed0a]
/home/ralf/sage/local/lib/python2.7/site-packages/sage/rings/polynomial/polynomial_zmod_flint.so(+0x1c92f)[0x7f1202c1092f]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0x4c9f3)[0x7f127fe639f3]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x4382)[0x7f127ff0bc62]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x85de)[0x7f127ff0febe]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0x79373)[0x7f127fe90373]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyObject_Call+0x5c)[0x7f127fe6640c]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0x6059e)[0x7f127fe7759e]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyObject_Call+0x5c)[0x7f127fe6640c]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xb2e25)[0x7f127fec9e25]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyObject_Call+0x5c)[0x7f127fe6640c]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x2675)[0x7f127ff09f55]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb391)[0x7f127ff12391]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0x79373)[0x7f127fe90373]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyObject_Call+0x5c)[0x7f127fe6640c]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0x6059e)[0x7f127fe7759e]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyObject_Call+0x5c)[0x7f127fe6640c]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xb3df9)[0x7f127fecadf9]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xafe86)[0x7f127fec6e86]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyObject_Call+0x5c)[0x7f127fe6640c]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x2675)[0x7f127ff09f55]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb391)[0x7f127ff12391]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(+0xfb2a8)[0x7f127ff122a8]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x24d5)[0x7f127ff09db5]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x894)[0x7f127ff07684]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyEval_EvalCode+0x1f)[0x7f127ff06ddf]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyRun_FileExFlags+0xa4)[0x7f127ff32ad4]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(PyRun_SimpleFileExFlags+0x2fc)[0x7f127ff3260c]
/home/ralf/sage/local/lib/libpython2.7.so.1.0(Py_Main+0xc23)[0x7f127ff47b13]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x7f127f171725]
/home/ralf/sage/local/bin/python2(_start+0x29)[0x4006d9]
------------------------------------------------------------------------

**********************************************************************
----------------------------------------------------------------------
sage -t --long --warn-long 49.8 src/sage/libs/flint/nmod_poly_linkage.pxi  # Timed out (and interrupt failed)

Running the exact above command manually passes fine.

Component: interfaces

Issue created by migration from https://trac.sagemath.org/ticket/25804

[jdemeyer]

comment:1

Basically, this cannot be fixed. See #16850 for the underlying issue.

How often does this crash?

[rwst]

comment:2

I don't run often make ptestlong. If this exists that long, though, it would happen here in less than 10% of runs.