#8580: bug in matrix_mod2_dense (m4ri wrapper?): exhibited by bug in coercing
into
a 0-dimensional qotient vector space
------------------------------+---------------------------------------------
Reporter: was | Owner: was
Type: defect | Status: new
Priority: major | Milestone: sage-4.4
Component: linear algebra | Keywords:
Author: | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
------------------------------+---------------------------------------------
Old description:
> {{{
> wst...@boxen:~$ /usr/local/bin/sage
> ----------------------------------------------------------------------
> | Sage Version 4.3.4, Release Date: 2010-03-19 |
> | Type notebook() for the GUI, and license() for information. |
> ----------------------------------------------------------------------
> sage: V = GF(2)^3
> sage: (V/V)(V.0)
>
> ------------------------------------------------------------
> 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).
> ------------------------------------------------------------
> }}}
New description:
{{{
wst...@boxen:~$ /usr/local/bin/sage
----------------------------------------------------------------------
| Sage Version 4.3.4, Release Date: 2010-03-19 |
| Type notebook() for the GUI, and license() for information. |
----------------------------------------------------------------------
sage: V = GF(2)^3
sage: (V/V)(V.0)
------------------------------------------------------------
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 is because of a bug in m4ri (or our wrapper of it), since with p=3
(instead of 2) everything works fine:
{{{
sage: V = GF(3)^3
sage: (V/V)(V.0)
()
sage:
}}}
--
Comment(by was):
With GDB:
{{{
This GDB was configured as "x86_64-linux-gnu"...
[Thread debugging using libthread_db enabled]
Python 2.6.4 (r264:75706, Mar 20 2010, 18:30:21)
[GCC 4.2.4 (Ubuntu 4.2.4-1ubuntu4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
[New Thread 0x7fd3670706e0 (LWP 623)]
sage: V = GF(2)^3
sage: (V/V)(V.0)
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fd3670706e0 (LWP 623)]
mzd_submatrix (S=0x41f5410, M=0x0, startrow=0, startcol=0, endrow=1,
endcol=0) at src/packedmatrix.c:810
810 src/packedmatrix.c: No such file or directory.
in src/packedmatrix.c
(gdb)
(gdb)
(gdb) bt
#0 mzd_submatrix (S=0x41f5410, M=0x0, startrow=0, startcol=0, endrow=1,
endcol=0)
at src/packedmatrix.c:810
#1 0x00007fd3471bf48a in
__pyx_pf_4sage_6matrix_17matrix_mod2_dense_17Matrix_mod2_dense_row (
__pyx_v_self=0x7fd366ec82f8, __pyx_args=<value optimized out>,
__pyx_kwds=<value optimized out>)
at sage/matrix/matrix_mod2_dense.c:4478
#2 0x000000000041a27d in PyObject_Call (func=0x4308758, arg=0xe9c050,
kw=0x0)
at Objects/abstract.c:2492
#3 0x00007fd34a198f6f in
__pyx_pf_4sage_6matrix_7matrix1_6Matrix_dense_rows (
__pyx_v_self=0x7fd366ec82f8, __pyx_args=<value optimized out>,
__pyx_kwds=<value optimized out>)
at sage/matrix/matrix1.c:5524
#4 0x000000000041a27d in PyObject_Call (func=0x422dfc8,
arg=0x7fd367030050, kw=0x4356d80)
at Objects/abstract.c:2492
#5 0x00000000004907c6 in PyEval_CallObjectWithKeywords (func=0x422dfc8,
arg=0x7fd367030050,
kw=0x4356d80) at Python/ceval.c:3575
#6 0x00007fd34a19b316 in __pyx_pf_4sage_6matrix_7matrix1_6Matrix_rows
(__pyx_v_self=0x7fd366ec82f8,
__pyx_args=<value optimized out>, __pyx_kwds=<value optimized out>) at
sage/matrix/matrix1.c:4990
#7 0x000000000041a27d in PyObject_Call (func=0x43087a0,
arg=0x7fd367030050, kw=0x4356530)
at Objects/abstract.c:2492
#8 0x00000000004907c6 in PyEval_CallObjectWithKeywords (func=0x43087a0,
arg=0x7fd367030050,
kw=0x4356530) at Python/ceval.c:3575
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8580#comment:1>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
