Build errors with the latest gfortran

[iii-i]

Hi!

I'm trying to build WRF with gfortran 10.0.1 20200226 (git commit ce25177f505). It looks as if it does not allow passing COMPLEX arrays as REAL ones anymore, since I'm getting a lot of error messages like the following:

zmfm1b.f90:70:38:

   68 |       call zmf2kb ( lot, ido, l1, na, c, jump, inc, ch, 1, lot, wa(iw) )
      |                                      2
   69 |     else if ( nbr == 2 ) then
   70 |       call zmf2kb ( lot, ido, l1, na, ch, 1, lot, c, jump, inc, wa(iw) )
      |                                      1
Error: Type mismatch between actual argument at (1) and actual argument at (2) (REAL(8)/COMPLEX(8)).

[davegill]

I will check on the status of FFTPACK, which is from where we took this code. If that has not been updated, we may be stuck with GNU 9 for a while.

[mgduda]

The GCC 10 documentation mentions the following:

Mismatches between actual and dummy argument lists in a single file are now rejected with an error. Use the new option -fallow-argument-mismatch to turn these errors into warnings; this option is implied with -std=legacy. -Wargument-mismatch has been removed.

Does adding the -fallow-argument-mismatch flag allow WRF to compile?

[iii-i]

@mgduda that helped, thanks!

I will leave the issue open for you to decide whether you'd like to improve gfortran 10 compatibility, or whether -fallow-argument-mismatch/-std=legacy is good enough.

[syalavarthi]

Duplicate of #1250