Currently, environment-variables in modules.yaml are consequently casted to uppercase.

In packages like Ice-T it's actually relevant if ICET_DIR or IceT_DIR is set in the environment, since only the latter is honored by CMake properly.

Probably, we should not change the spelling of such variables if the user sets them explicitly. This "cast-to-uppercase" was probably added because generic syntax such as

      environment:
        set:
          '${PACKAGE}_ROOT': '${PREFIX}'

is allowed which usually needs the package name in uppercase.

Example snippet that breaks my IceT hint:

modules:
  enable::
    - lmod
  lmod:
    core_compilers:
      - 'gcc@5.4.0'
    hash_length: 0
    gcc:
      environment:
        set:
          CC: gcc
          CXX: g++
          FC: gfortran
          F90: gfortran
          F77: gfortran
    openmpi:
      environment:
        set:
          OMPI_MCA_mpi_leave_pinned: '0'
    icet:
      environment:
        set:
          IceT_DIR: '${PREFIX}/lib'

does not set and IceT_DIR but an ICET_DIR.

Both cases are actually only triggered by a double-inconsistency in IceT:

• it's CMake config scripts are installed at the wrong place and
• all CMake ENV var hints are traditionally UPPERCASE (and only CMake vars are case-sensitive)

Therefore we could also decide to just ignore that problem and I could try to work-around it via:

    icet:
      environment:
        prepend_path:
          CMAKE_PREFIX_PATH: '${PREFIX}/lib'

which is luckily already uppercase.

The same happens to OMPI_MCA_mpi_leave_pinned (-> OMPI_MCA_MPI_LEAVE_PINNED) above, where I am not sure if the spelling might again be critical for MPI's understanding of it.

ccing @alalazo