It materializes as

[  559s]
../../special/tests/test_kolmogorov.py::TestSmirnovp::test_oneminusoneovern <-
../../../../../usr/lib/python3.9/site-packages/scipy/special/tests/test_kolmogorov.py
Fatal Python error: Floating point exception
[  559s]
[  559s] Current thread 0xf7970700 (most recent call first):
[  559s]   File "/usr/lib/python3.9/site-packages/scipy/special/_testutils.py",
line 213 in eval_func_at_params

with gdb one sees

Thread 1 "python3.9" received signal SIGFPE, Arithmetic exception.
0xd059330b in pow2Scaled_D (a=..., m=8, pExponent=0xffff81f0) at
scipy/special/cephes/kolmogorov.c:607
607         y2r = pow2Scaled_D(y, r, &y2rE);

   0xd05932f0 <+336>:   mov    0xe0(%esp),%eax
   0xd05932f7 <+343>:   movaps %xmm0,0x60(%esp)
   0xd05932fc <+348>:   lea    0x9c(%esp),%ebp
   0xd0593303 <+355>:   sub    $0x8,%esp
   0xd0593306 <+358>:   mov    %ecx,0x10(%esp)
   0xd059330a <+362>:   cltd   
=> 0xd059330b <+363>:   idiv   %ecx
   0xd059330d <+365>:   mov    %eax,0x18(%esp)
   0xd0593311 <+369>:   lea    0x48(%esp),%ecx

and we divide by zero.

(gdb) l
602         }
603
604         q = m / maxExpt;
605         r = m % maxExpt;
606         /* y^m = (y^maxExpt)^q * y^r */
607         y2r = pow2Scaled_D(y, r, &y2rE);
608         y2m = pow2Scaled_D(y, maxExpt, &y2mE);
609         y2mq = pow2Scaled_D(y2m, q, &y2mqE);
610         ans = frexpD(mul_DD(y2r, y2mq), &ansE);
611         y2mqE += y2mE * q;
(gdb) p maxExpt
$7 = 0