[Bug fortran/79087] New: CPATH environment variable not recognised.

["w6ws at earthlink dot net" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79087

            Bug ID: 79087
           Summary: CPATH environment variable not recognised.
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: w6ws at earthlink dot net
  Target Milestone: ---

The ENVIRONMENT portion of the gfortran man page states:

       The gfortran compiler currently does not make use of any environment
       variables to control its operation above and beyond those that affect
       the operation of gcc.

Then referring to the ENVIRONMENT portion of the gcc man page, under CPATH, it
states:

           CPATH specifies a list of directories to be searched as if
           specified with -I, but after any paths given with -I options on the
           command line.  This environment variable is used regardless of
           which language is being preprocessed.

Unfortunately gfortran does not seem to recognize CPATH:

wws@w6ws-4:~$ cd /tmp
wws@w6ws-4:/tmp$ mkdir include
wws@w6ws-4:/tmp$ cat > include/inc.inc
      integer, parameter :: answer = 42
wws@w6ws-4:/tmp$ export CPATH=/tmp/include
wws@w6ws-4:/tmp$ cat > junk.f90
program junk
  include "inc.inc"
  print *, answer
end program
wws@w6ws-4:/tmp$ gfortran junk.f90
junk.f90:2: Error: Can't open included file 'inc.inc'
wws@w6ws-4:/tmp$ gfortran -I$CPATH junk.f90
wws@w6ws-4:/tmp$ a.out
          42
wws@w6ws-4:/tmp$ /tmp$ gfortran --version
GNU Fortran (GCC) 7.0.0 20160831 (experimental)
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

wws@w6ws-4:/tmp$ 

Intel Fortran does support this.  It is handy when used in conjunction with the
"module" package that is often used at sites to select various software
packages.

This ticket might be a duplicate of PR 65998, but that ticket seems more
pre-processor (cpp) and architecture oriented.