Urgent Help with WRF Compilation Failure - "Problems building executables" in WSL Ubuntu

[jitendra_bhilala]

Dear WRF Support Team,

I am Jitendra Bhilala (jitendra.bhilala@tropmet.res.in), a researcher at IITM trying to install WRF-Hydro-iso-tag (isotope-enabled WRF-Hydro v5.0 fork from Figshare: https://figshare.com/articles/code/WRF-Hydro-iso-tag_source_code_and_test_case/18523733) on WSL Ubuntu 24.04 for my water isotope simulations. I've followed the README (readme_WRF-Hydro-iso-tag_compilation and readme_TestCase), but compilation fails at linking.


Setup:

• WSL Ubuntu 24.04 (GNU/Linux 6.6.87.2-microsoft-standard-WSL2).
• Dependencies: gfortran, mpich, libnetcdf-dev, libnetcdff-dev, libhdf5-dev (installed via apt).
• Env vars: NETCDF_classic=1, WRF_HYDRO=1, ISO_TAG=1, FC=gfortran, CC=gcc, MPIFC=mpif90, MPICC=mpicc.
• Source: Extracted from Figshare tar.gz (~2.3 GB).

Steps Taken:

1. ./clean -a
2. ./configure (selected 34 for GNU dmpar, 1 for basic nesting).
3. ./compile em_real

Error:

• Build runs ~3-4 min, then:
  text
  
  build completed: Mon Dec 15 12:00:54 UTC 2025
  ---> Problems building executables, look for errors in the build log <---
  
  
• No main/wrf.exe generated.
• Log (compile.log not generated; from terminal tail):
  • Type mismatches (INTEGER(4)/REAL(4), REAL(4) to REAL(8)).
  • Fatal: Cannot open module file ‘module_check_a_mundo.mod’ for reading.
  • ld returned 1 exit status.
• Full log snippet (from redirected output):
  text
  
  Error: Type mismatch between actual argument at (1) and actual argument at (2) (INTEGER(4)/REAL(4)).
  Fatal Error: Cannot open module file ‘module_check_a_mundo.mod’ for reading at (1): No such file or directory
  make[1]: [../configure.wrf:348: ndown_em.o] Error 1 (ignored)
  collect2: error: ld returned 1 exit status
  

Tried Fixes:

• Added -lz -lm to LIB_EXTERNAL, NETCDFLIB, HDF5LIB in configure.wrf.
• Enabled PROMOTION = -fdefault-real-8.
• Full clean/re-configure.
• No luck—still "Problems building".

I have also attempted the compilation on an HPC cluster (ARKA at IITM) using Intel compilers (ifort/icc 2020.4.304 with Intel MPI) and custom NetCDF/HDF5 paths, but encountered the same linking failure ("Problems building executables"). The issue persists across environments, suggesting a configuration or dependency mismatch specific to the iso-tag fork.

Is there a WSL-specific manual or fix for iso-tag? Any pre-built binaries or Docker image? Please reply ASAP—I'm stuck for my research.


Thanks,
Jitendra Bhilala
IITM
jitendra.bhilala@tropmet.res.in