Cannot build against wgrib2api on Orion and Hercules (spack-stack 1.6.0)

[DavidHuber-NOAA]

Describe the bug
When attempting to build gfs-utils on Orion or Hercules with wgrib2api.mod, the compiler is unable to find the module. The gfs-utils branch used for this work is DavidHuber-NOAA:feature/ss160. This version does build on Hera. The gfs-utils module that uses the API is src/reg2grb2.fd/regdiag.f.

To Reproduce

git clone git@github.com:DavidHuber-NOAA/gfs-utils -b feature/ss160
cd gfs-utils/ush
./build.sh

Expected behavior
gfs-utils would be able to build against wgrib2api on all platforms.

System:
Hercules (possibly others, but not Hera)

Additional context
Found while upgrading the global workflow to spack-stack version 1.6.0 (NOAA-EMC/global-workflow#2195).

[climbfuji]

I wonder if that's because the wgrib2 build failed silently. Previously, we had to pin wgrib to a newer version (3.1.1) to avoid build errors on Hercules. With the last release, this wasn't necessary, but perhaps this was a false positive and the 2.0.8 build failed silently without causing spack install to abort.

[climbfuji]

@DavidHuber-NOAA I'll start looking into this today

[climbfuji]

Well, after Hercules recovered from the power outage ... Orion is offline today, too.

[DavidHuber-NOAA]

This problem is also present on Orion. I'll update the description.

[DavidHuber-NOAA]

Actually, it looks like the wrong version of wgrib2 is being loaded. The gfs-utils modulefile requests version 2.0.8, but the system version 3.1.1 is being loaded instead, which does not include the wgrib2api.mod module. I fixed this for Orion, but will need to work a little more on Hercules. Closing this issue and will track further work in NOAA-EMC/gfs-utils#43.