I am trying to install r.inund.fluv on Linux to produce inundation maps but I am getting the below error. Note that I have a Fortran compiler.
GRASS 6.4.4 (newLocation):~ > g.extension r.inund.fluv
Fetching <r.inund.fluv> from GRASS-Addons SVN (be patient)...
A r.inund.fluv/r.inund.fluv_62
A r.inund.fluv/correction_from_path.f90
A r.inund.fluv/clean_inundation.f90
A r.inund.fluv/r.inund.fluv
A r.inund.fluv/find_main_channel.f90
A r.inund.fluv/README.txt
A r.inund.fluv/r.inund.fluv.html
A r.inund.fluv/Makefile
A r.inund.fluv/2d_path.f90
Checked out revision 65521.
Compiling <r.inund.fluv>...
Makefile:4: /usr/lib64/grass-6.4.4/include/Make/Script.make: No such file or directory
Makefile:5: /usr/lib64/grass-6.4.4/include/Make/Module.make: No such file or directory
make: *** No rule to make target `/usr/lib64/grass-6.4.4/include/Make/Module.make'. Stop.
ERROR: Compilation failed, sorry. Please check above error messages.