segmentation fault contraction tensor

[LBrunswic]

The following code generates a segfault in sage-shell. In the notebook, we get a TypeError and a kernel crash.

Parallelism().set(nproc=2) 
M = FiniteRankFreeModule(SR, 3, name='M')
e  = M.basis('e')
x,y,z,t = var("x,y,z,t")                 
Theta = M.tensor((1,1))
for i in range(3):
    for j in range(3):
        Theta[i,j] = function("Theta_"+str(i)+str(j))(x,y,z,t)
Theta["^i_j"]*Theta["^j_i"]  

Note that the error does not occur if one replaces
Parallelism().set(nproc=2)
by
Parallelism().set(nproc=1)

Furthermore, this error did not occur in sage8.9

CC: @egourgoulhon

Component: linear algebra

Keywords: Tensors, parallelism, segmentation fault

Author: Léo Brunswic

Reviewer: Eric Gourgoulhon

Issue created by migration from https://trac.sagemath.org/ticket/28798

[LBrunswic]

comment:1

I Tried to find a simpler version of the bug. It does not occur if one replace symbolic functions by a variable.

[egourgoulhon]

comment:2

This is a duplicate of #27492.

[LBrunswic]

comment:3

I'm sorry!

[egourgoulhon]

comment:4

Replying to @LBrunswic:

I'm sorry!

No problem.
Before opening a ticket for a bug, you may have a look at the bug section of the metaticket #18528 to check if a ticket has not been already opened.

[egourgoulhon]

comment:5

I am marking the ticket as "positive review" so that it can be closed with the resolution flag set to duplicate.

[egourgoulhon]

Reviewer: Eric Gourgoulhon