[Users] environmental variables in Cactus configuration files

[Miguel Zilhão]

hi all,

i'm compiling ET on a local cluster that uses the module system. on this system, once one does 
"module load <...>", the respective path is added to an environmental variable. for instance, doing

  $ module load HDF5

sets the environmental variable $EBROOTHDF5:

  $ echo $EBROOTHDF5
  /home/share/easybuild/software/HDF5/1.8.20-GCC-7.3.0-2.30-generic

so i was trying to use these in my configuration file, by adding the lines

  HDF5_DIR       = $EBROOTHDF5
  HDF5_LIB_DIRS  = ${EBROOTHDF5}/lib
  HDF5_INC_DIRS  = ${EBROOTHDF5}/include

etc, to it. however, these environmental variables don't seem to be correctly expanded, as i get 
things like the following:

  Running configuration script for thorn HDF5:
  Additional requested language support:  Fortran
  WARNING in HDF5 configuration:
  None of H5pubconf.h H5pubconf-64.h H5pubconf-32.h found in ${EBROOTHDF5}/lib ${EBROOTHDF5}/include
  Automatic detection of szip/zlib compression not possible
  Finished running configuration script for thorn HDF5.

but if i look into the folder ${EBROOTHDF5}/include, these files are clearly there. the compilation 
later fails because of this.

when i specify the full path explicitly in the config file:

  HDF5_INC_DIRS  = /home/share/easybuild/software/HDF5/1.8.20-GCC-7.3.0-2.30-generic/include

i get no such warnings, and the code proceeds to compile just fine. is this the expected behaviour? 
shouldn't the environmental variables be correctly expanded? if not, what would be the typical 
procedure to compile the code on systems with such module tools?

thanks,
Miguel