Dear maintainer:

During a rebuild of all packages in unstable, this package failed to build.

The build never ended and the process had to be killed by hand,
which means not even sbuild's built-in timeout mechanism worked this time.

This used to work ok on 2026-08-03 and it already failed on 2026-08-22,
but I don't have intermediate data.

Below you will find the last part of the build log (probably the most
relevant part, but not necessarily). If required, the full build log
is available here:

https://people.debian.org/~sanvila/build-logs/202608/

About the archive rebuild: The build was made on virtual machines from AWS,
using sbuild and a reduced chroot with only build-essential packages.

If you cannot reproduce the bug please contact me privately, as I
am willing to provide ssh access to a virtual machine where the bug is
fully reproducible.

If this is really a bug in one of the build-depends, please use
reassign and add an affects on src:octave-symbolic, so that this is still
visible in the BTS web page for this package.

Thanks.
--------------------------------------------------------------------------------
[...]
***** test
 % return empty string (was https://bugs.python.org/issue25270)
 assert (isempty (pycall_sympy__ ('return ""')))
***** test
 % return nothing (via an empty list)
 % note distinct from 'return [],'
 pycall_sympy__ ('return []')
***** test
 % return nothing (because no return command)
 pycall_sympy__ ('dummy = 1')
***** test
 % return nothing (because no command)
 pycall_sympy__ ('')
***** test
 % return nothing (because no command)
 pycall_sympy__ ({})
***** error <AttributeError>
 % python exception while passing variables to python
 % This tests the "INTERNAL_PYTHON_ERROR" path.
 % FIXME: this is a very specialized test, relies on internal octsympy
 % implementation details, and may need to be adjusted for changes.
 disp('')
 disp('**********************************************************************')
 disp('')
 disp('  Some deliberate AttributeError and ValueError may appear next')
 disp('')
 disp('v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v')
 b = sym([], 'S.This_is_supposed_to_make_an_exception', [1 1], 'Test', 'Test', 'Test');
 c = b + 1;

**********************************************************************

  Some deliberate AttributeError and ValueError may appear next

v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v  v
Traceback (most recent call last):
  File "<stdin>", line 4, in <module>
    _ins.append(S.This_is_supposed_to_make_an_exception)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/sympy/core/singleton.py", line 143, in __getattr__
    raise AttributeError(
        "Attribute '%s' was not installed on SymPy registry %s" % (
        name, self))
AttributeError: Attribute 'This_is_supposed_to_make_an_exception' was not installed on SymPy registry S
Waiting.......................................................................................................................................................................................................................................................................................................................................................................................................................
--------------------------------------------------------------------------------