[ccache] Fortran support issue

[Giacomo Comes]

Hi,
I have been using in the past the program f90cache to cache
fortran compiling jobs.
Now that ccache 3.3 has support for Fortran 77 I have
done some tests to see if I can replace f90cache with ccache.
So far all the fortran programs I'm used to compile works with ccache except one.
The source is available here:
  http://water.usgs.gov/ogw/modflow/MODFLOW-2005_v1.11.00/mf2005v1_11_00_unix.zip
I unzip it, then run:
  cd Unix/src
  sed -i '/^F90=/s/=.*/=ccache gfortran/;/^CC=/s/=.*/=ccache gcc/' makefile
  make
The program will compile without errors.
Now if I delete the source and redo the same procedure (unzip and compile)
after I run make I get:
-------------------------------------------------------------------------
ccache gfortran  -c gwf2bas7.f
ccache gfortran  -c de47.f
ccache gfortran  -c pcg7.f
ccache gfortran  -c sip7.f
ccache gfortran  -c gmg7.f
ccache gfortran  -c mhc7.f
ccache gfortran  -c pcgn_solve2.f90
ccache gfortran  -c pcgn2.f90
pcgn2.f90:24.6:

  USE GLOBAL, ONLY: IOUT, NCOL, NROW, NLAY, NODES
      1
Fatal Error: Can't open module file 'global.mod' for reading at (1): No such file or directory
makefile:101: recipe for target 'pcgn2.o' failed
make: *** [pcgn2.o] Error 1
-------------------------------------------------------------------------
Again, with f90cache everything works ok.
Tested with ccache 3.3.2

Giacomo