https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125267
--- Comment #6 from Jürgen Reuter <juergen.reuter at desy dot de> ---
It is the -fcheck=bounds flag that causes the problems, here is the complete
backtrace (I will try to shrink the reproducer now), w.r.t. to the 2nd
reproducer above:
olarizations.polarizations_s::pmatrix_normalize (pmatrix=..., flv=...,
degree=1, tolerance=1e-08) at polarizations_sub.f90:646
646 if (index(1) == index(2)) then
(gdb) bt
#0 polarizations.polarizations_s::pmatrix_normalize (pmatrix=..., flv=...,
degree=1, tolerance=1e-08) at polarizations_sub.f90:646
#1 0x000000000046bcad in polarizations_uti::polarization_2 (u=12) at
polarizations_uti.f90:245
#2 0x000000000040a766 in unit_tests.unit_tests_s::test (test_proc=0x46b130
<polarizations_uti::polarization_2>, name=..., description=..., u_log=11,
results=..., _name=_name@entry=14,
_description=25) at unit_tests_sub.f90:156
#3 0x0000000000470e89 in polarizations_ut::polarizations_test (u=11,
results=...) at polarizations_ut.f90:48
#4 0x0000000000471df1 in whizard_check ()
#5 0x000000000047295d in MAIN__ ()