legacy support issue while building cmake (Leopard)

[rmottola (Riccardo)]

I am unable to build cmake on Leopard i386 I tried clang 3.9 and 5.0, I get the same output:

In file included from /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_cmake/cmake/work/cmake-3.14.5/Source/cmLinkedTree.h:8:
In file included from /usr/include/assert.h:44:
/opt/local/include/LegacySupport/stdlib.h:44:14: error: conflicting asm label
extern char *realpath(const char * __restrict, char * __restrict)
             ^
/usr/include/stdlib.h:226:60: note: previous declaration is here
char    *realpath(const char * __restrict, char * __restrict) __DARWIN_EXTSN(realpath);
                                                              ^
/usr/include/sys/cdefs.h:365:36: note: expanded from macro '__DARWIN_EXTSN'
#define __DARWIN_EXTSN(sym)             __asm("_" __STRING(sym) __DARWIN_SUF_EXTSN)
                                              ^
1 error generated.
gmake: *** [Makefile:6: cmAddCustomTargetCommand.o] Error 1
gmake: *** Waiting for unfinished jobs....
1 error generated.
gmake: *** [Makefile:4: cmAddCustomCommandCommand.o] Error 1

I suppose this is more LegacySupport issue than cmake, a redefiition of realpath