https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96486
--- Comment #9 from kargl at gcc dot gnu.org --- (In reply to kargl from comment #5) > (In reply to Susi Lehtola from comment #4) > > $ export HOSTNAME=foo > > $ ./a.out > > $ > > > > $ export HOSTNAME= > > $ ./a.out > > Fortran runtime error: Zero-length string passed as value to > > get_environment_variable. > > > > Error termination. Backtrace: > > #0 0x7f25c93aadf1 in ??? > > #1 0x7f25c93ab939 in ??? > > #2 0x7f25c93abe60 in ??? > > #3 0x7f25c960ce53 in ??? > > #4 0x401267 in ??? > > #5 0x4012c4 in ??? > > #6 0x7f25c903a041 in __libc_start_main > > at ../csu/libc-start.c:308 > > #7 0x4010ad in ??? > > #8 0xffffffffffffffff in ??? > > $ > > Thanks. > > What gfortran version and operating system? I get > > % gfcx -o z b.f90 && ./z > STOP System variable unassigned > % gfcx -o z -g b.f90 && ./z > STOP System variable unassigned > % gfcx -o z -g -O b.f90 && ./z > STOP System variable unassigned > > with your code where gfcx is gfortran 10.0.0 (Jan 2020 vintage) > and I'm using i585-*-freebsd. Whoops. Misread part of bug report. With tcsh, I see % setenv HOSTNAME '' % gfcx -o z -g -O b.f90 && ./z Fortran runtime error: Zero-length string passed as value to get_environment_variable. and unsetenv HOSTNAME % setenv HOSTNAME % gfcx -o z -g -O b.f90 && ./z Fortran runtime error: Zero-length string passed as value to get_environment_variable. No backtrace. Can you compile with -g, run the executable under gdb, and post the backtrace.
