[Bug fortran/96486] get_environment_variable fails for zero-length values

[jussilehtola at fedoraproject dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96486

--- Comment #16 from Susi Lehtola <jussilehtola at fedoraproject dot org> ---
Yes, then I installed missing libgfortran debuginfos and the backtrace
shortened to

#0  0x401267 in zerolen_value
        at /tmp/readvar2.f90:17
#1  0x4012c4 in main
        at /tmp/readvar2.f90:22