fms: add 2025.04, 2026.01

[mathomp4]

I noticed FMS released 2026.01 recently and that 2025.04 wasn't in here.

cc: @rem1776 in case FMS 2026 has any sort of "extra" dependencies I'm not aware of.

[climbfuji]

Defer to @rem1776 for changes to build variants.

[mathomp4]

Defer to @rem1776 for changes to build variants.

Ohh. Maybe there are some. I just saw that the libyaml handling in FMS 2026.01 CMake is different

I'm not too conversant on PkgConfig and CMake. Let me do a quick test build and see.

---

Oh, and note to @climbfuji (and @rem1776) I hope to soon figure out a good patch to work around NOAA-GFDL/FMS#1809 for ifx until a fix can go in in 2026.02+.

I think it's pretty simple. Just if ifx 2025.3 remove that one line in a cmake file.

But for now, I wanted to get this in.

[rem1776]

@mathomp4 @climbfuji

In 2025.04 there were some slight changes to the real precision option.

We didn't modify the existing 32/64 bit options, but now if neither are specified it will build with r8 defaults and exclude the r4/r8 suffix in the library name. I don't think that will break anything with the spack configuration as is.

For both versions there shouldn't be any changes in dependencies, we just modified the cmake build to use pkg-config to find libyaml in the 2026.01 release. I hope that is not problem for the spack build, usually just comes down to if the PKG_CONFIG_PATH is set properly.

[mathomp4]

@rem1776 Uh oh. I get a lot of:

  >> 49      CMake Error at CMakeLists.txt:615 (target_link_libraries):
     50        Target "testLibs" links to:
     51
     52          FMS::fms
     53
     54        but the target was not found.  Possible reasons include:
     55
     56          * There is a typo in the target name.
     57          * A find_package call is missing for an IMPORTED target.
     58          * An ALIAS target is missing.

for various targets.

I'm drafting this for now until I can figure it out.

[mathomp4]

Update. I can get precision=none to work (aka the mixed-precision).

But when I try and do any of:

• spack install fms@2026.01 precision=32
• spack install fms@2026.01 precision=64
• spack install fms@2026.01 precision=32,64

they all fail like:

  >> 48      CMake Error at CMakeLists.txt:615 (target_link_libraries):
     49        Target "testLibs" links to:
     50
     51          FMS::fms
     52
     53        but the target was not found.  Possible reasons include:
     54
     55          * There is a typo in the target name.
     56          * A find_package call is missing for an IMPORTED target.
     57          * An ALIAS target is missing.

I try this some more soon.