xPerm : unable to connect to the external executable

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Nux

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Nov 24, 2023, 1:00:49 PM11/24/23
to xAct Tensor Computer Algebra
Hi,

First, as information, I'm working on Mathematica 13.0 on a Fedora 37 distrib.
I've installed xAct following the installation notes (tried the system wide and single user one, before posting here). However it seems impossible to import xPerm : it gets stuck on the "Connecting to external linux executable...".
Moreover, I can import xTensor, xCore, xCoba without any issues to connect to the external executable. (Still, since xTensor import xPerm, I need to execute << xAct`xTensor`;, abort, and then execute it again, probably because it updates the ContextPath and then skip the import of xPerm.)

I've also tried to recompile xPerm using mprep and mcc, but still the same issue in the end.

I'd like to add that however :

$xpermLink =Install["path/to/xperm.linux"]

return a LinkObject without any issues. But in the end, since stuff like $xpermQ and such are undefined, it does not work when working on real stuff.

Is there any idea on what to do at this point ?

Thank you !

Ilham Prasetyo

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Dec 16, 2025, 2:04:16 AM (2 days ago) Dec 16
to xAct Tensor Computer Algebra
Hello guys,

I am currently experiencing the same. I have Mathematica 12 in Fedora 43. As far as I have know, xPert and xPerm are stuck on "Connecting to external linux executable...". It seems this bug is still there from 2 years ago. Is there any update about this?

Regards,
Ilham

Thomas Bäckdahl

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Dec 17, 2025, 9:13:49 AM (21 hours ago) Dec 17
to xa...@googlegroups.com
Hi!

xAct really needs a new release. Mathematica changes the versions of the mathlink communication protocol from time to time. There are also name conflicts with the newest version of Mathematica.

In the meantime. What have you tried?

If you have not tried it already, try
cd ~/.Wolfram/Applications/xAct/xPerm/mathlink
mcc xperm.tm -O3 -o xperm.linux.64-bit

This should recompile the external mathlink file to fit your system.

Regards
Thomas
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Ilham Prasetyo

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3:59 AM (2 hours ago) 3:59 AM
to xAct Tensor Computer Algebra
Thank you for the guidance.

Firstly, I am trying Fedora in vmWare, actually. I just want to test it before migrating from Win11 to Fedora.
Secondly, Mathematica 12 in Fedora 43 weirdly cannot find xAct folder in ~/.Wolfram/Applications/ but it can if I change it to ~/.Mathematica/Applications/. Thus I just put xAct folder in both of them.

When I call xTensor in Mathematica, it gives me this:

------------------------------------------------------------
Package xAct`xCore`  version 0.6.10, {2018,2,28}
CopyRight (C) 2007-2020, Jose M. Martin-Garcia, under the General Public License.
------------------------------------------------------------
This package comes with ABSOLUTELY NO WARRANTY; for details type Disclaimer[]. This is free software, and you are welcome to redistribute it under certain conditions. See the General Public License for details.
------------------------------------------------------------
------------------------------------------------------------
Package xAct`xPerm`  version 1.2.3, {2015,8,23}
CopyRight (C) 2003-2020, Jose M. Martin-Garcia, under the General Public License.

Connecting to external linux executable...
LinkOpen::linke: Could not find MathLink executable.

Lastly, I had done using mcc. It is still give error like below.

$ mcc xperm.tm -O3 -o xperm.linux.64-bit
xperm.linux.64-bit.tm.c: xperm.tm: In function ‘main’:
xperm.tm:573:5: warning: old-style function definition [-Wold-style-definition]
  573 | int main(argc, argv)
      |     ^~~~
In file included from xperm.tm:24:
In function ‘copy_list’,
    inlined from ‘copy_list’ at xperm.c:283:6,
    inlined from ‘sort’ at xperm.c:389:2,
    inlined from ‘double_coset_rep’ at xperm.c:1973:2:
xperm.c:285:9: warning: ‘__builtin_memcpy’ writing between 18446744065119617024 and 18446744073709551612 bytes into a region of size between 0 and 9223372036854775807 [-Wstringop-overflow=]
  285 |         memmove(list2, list1, n*sizeof(int));
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xperm.c: In function ‘double_coset_rep’:
xperm.c:1738:35: note: destination object of size [0, 9223372036854775807] allocated by ‘malloc’
 1738 |         int *drummytmp2=    (int*)malloc(  n*sizeof(int));
      |                                   ^~~~~~~~~~~~~~~~~~~~~~~
In function ‘copy_list’,
    inlined from ‘copy_list’ at xperm.c:283:6,
    inlined from ‘sort’ at xperm.c:389:2,
    inlined from ‘double_coset_rep’ at xperm.c:1973:2:
xperm.c:285:9: warning: ‘__builtin_memcpy’ specified bound between 18446744065119617024 and 18446744073709551612 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
  285 |         memmove(list2, list1, n*sizeof(int));
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: cannot find -luuid: No such file or directory
collect2: error: ld returned 1 exit status

I am confused. Any suggestions?

Regards,
Ilham

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