#4527 closed defect (fixed)
[with patch, with positive review] Exception in 'sage.matrix.matrix_integer_dense.Matrix_integer_dense._hnf_modn_impl'
Reported by: | syazdani | Owned by: | craigcitro |
---|---|---|---|
Priority: | major | Milestone: | sage-3.2 |
Component: | modular forms | Keywords: | segfault |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
Hi,
the following code raises an exception that crashes sage on my computer:
cond=206 J=J0(206) D=J.new_subvariety().decomposition() Jp=J.old_subvariety(2) Jpc=Jp.cuspidal_subgroup() Ac=D[3].cuspidal_subgroup() Ac.intersection(Jpc)
The error I get (running it through the notebook) is
Exception in 'sage.matrix.matrix_integer_dense.Matrix_integer_dense._hnf_modn_impl' ignored ------------------------------------------------------------ Unhandled SIGSEGV: A segmentation fault occured in SAGE. This probably occured because a *compiled* component of SAGE has a bug in it (typically accessing invalid memory) or is not properly wrapped with _sig_on, _sig_off. You might want to run SAGE under gdb with 'sage -gdb' to debug this. SAGE will now terminate (sorry). ------------------------------------------------------------
This seems very sensitive to the set of inputs, but it is consistent on my computer. I'm running sage 3.1.4 (release date 2008-10-20), on mandriva, compiled with gcc 4.2.2 20071128.
Soroosh
Attachments (2)
Change History (9)
comment:1 Changed 14 years ago by
- Component changed from algebra to modular forms
- Keywords segfault added
- Milestone set to sage-3.2.1
- Owner changed from tbd to craigcitro
comment:2 Changed 14 years ago by
- Summary changed from Exception in 'sage.matrix.matrix_integer_dense.Matrix_integer_dense._hnf_modn_impl' to [with patch; needs review] Exception in 'sage.matrix.matrix_integer_dense.Matrix_integer_dense._hnf_modn_impl'
comment:3 Changed 14 years ago by
- Milestone changed from sage-3.2.1 to sage-3.2
With the patch applied:
mabshoff@sage:/scratch/mabshoff/release-cycle/sage-3.2.rc1$ ./sage ---------------------------------------------------------------------- | Sage Version 3.2.rc0, Release Date: 2008-11-10 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: cond=206 sage: J=J0(206) sage: D=J.new_subvariety().decomposition() sage: Jp=J.old_subvariety(2) sage: Jpc=Jp.cuspidal_subgroup() sage: Ac=D[3].cuspidal_subgroup() sage: Ac.intersection(Jpc) Finite subgroup with invariants [] over QQ of Simple abelian subvariety 206d(1,206) of dimension 4 of J0(206)
I am currently running doctests.
Cheers,
Michael
comment:4 Changed 14 years ago by
With the patch applied doctests with "-long" pass. Note that the example posted that exposes the problem takes about 30 seconds CPU time, so we should add it as a "#long time" example unless someone comes up with a shorter one.
Cheers,
Michael
Changed 14 years ago by
comment:5 Changed 14 years ago by
- Summary changed from [with patch; needs review] Exception in 'sage.matrix.matrix_integer_dense.Matrix_integer_dense._hnf_modn_impl' to [with patch, with positive review] Exception in 'sage.matrix.matrix_integer_dense.Matrix_integer_dense._hnf_modn_impl'
Looks good. I added a doctest based on Soroosh's original example in the extra patch above.
comment:6 Changed 14 years ago by
- Resolution set to fixed
- Status changed from new to closed
Merged in Sage 3.2.rc1
comment:7 Changed 7 years ago by
- Description modified (diff)
- Report Upstream set to N/A
I can reproduce this with the latest and greatest Sage. Gdb says:
I am running the computation under valgrind now if it catches anything.
Cheers,
Michael