Build problem with cvs 1.11.6 on VMS

[Smit, Sander]

Hello, 

I've been trying to build cvs 1.11.6 client with DEC C V6.0-001 on
OpenVMS Alpha V6.2.
After fixing some duplicate definitions (mode_t, pid_t) and renaming
fcntl.h_in to fcntl.h I got stuck on the following errors:

ALPHA> @build_lib
$ set verify
$ CC :== CC/DEBUG/NOOPTIMIZE/STANDARD=VAXC/DEFINE=HAVE_CONFIG_H-
/INCLUDE_DIRECTORY=([-],[-.LIB],[-.SRC],[-.VMS])/PREFIX_LIBRARY_ENTRIES=ALL_ENTRIES
$ CC getopt.c

     char *const *argv;
..........^
%CC-E-PROMOTMATCH, In the definition of the function "cvs_getopt", the
promoted type of argv is incompatible with the type of the
corresponding parameter in a prior declaration.
at line number 674 in file API_DIS:[CVS.CVS-1_11_6.LIB]GETOPT.C;4

     const char *optstring;
................^
%CC-E-PROMOTMATCH, In the definition of the function "cvs_getopt", the
promoted type of optstring is incompatible with the type of the
corresponding parameter in a prior declaration.
at line number 675 in file API_DIS:[CVS.CVS-1_11_6.LIB]GETOPT.C;4

How do I get around this compile error? I don't know where to look for
the clashing prior declaration.
When I commented the entire 'getopt' function in getopt.c, I got more
than 1 (expected) unresolved external:

$ link/nodeb/exe=cvs.exe
main.obj,cvslib.olb/lib,[-.vms]openvmslib.olb/lib,-
    [-.zlib]libz.olb/lib,[-.diff]diff.olb/lib,[-.lib]gnulib.olb/lib
%LINK-W-NUDFSYMS, 5 undefined symbols:
%LINK-I-UDFSYM,         CVS_GETOPT 
%LINK-I-UDFSYM,         FCNTL 
%LINK-I-UDFSYM,         LOCATE_RCS 
%LINK-I-UDFSYM,         SYSCONF 
%LINK-I-UDFSYM,         UNLINK 
%LINK-W-USEUNDEF, undefined symbol CVS_GETOPT referenced
$ set noverify

Thanks in advance,
Sander