ld64 @236.3_1: build failure on 10.8 and earlier

[dbevans (David B. Evans)]

When building on OS X 10.8 and earlier build fails as follows:

/usr/bin/clang++ -Os -Os -stdlib=libstdc++ -arch x86_64 -I/opt/local/libexec/llvm-3.3/include -DLTO_SUPPORT -Isrc/abstraction -Isrc/ld -Isrc/ld/parsers -I/opt/local/include  -c -o src/other/dyldinfo.o src/other/dyldinfo.cpp
In file included from src/other/ObjectDump.cpp:35:
In file included from src/ld/parsers/macho_relocatable_file.h:28:
src/ld/ld.hpp:35:10: fatal error: 'unordered_set' file not found
#include <unordered_set>
         ^
In file included from src/ld/parsers/macho_relocatable_file.cpp:50:
src/ld/ld.hpp:35:10: fatal error: 'unordered_set' file not found
#include <unordered_set>
         ^
In file included from src/ld/parsers/lto_file.cpp:42:
src/ld/ld.hpp:35:10: fatal error: 'unordered_set' file not found
#include <unordered_set>
         ^
1 error generated.
make: *** [src/other/ObjectDump.o] Error 1

Observed locally and on buildbots. Build log (10.8) attached.

[dbevans (David B. Evans)]

ML log showing build error

[jwhowse4]

Cc Me!

[jwhowse4]

I get the same error on OS X 10.8 building with llvm-3.4.

[hapaguy (Brian Kurt Fujikawa)]

Cc Me!

[cjones051073 (Chris Jones)]

Cc Me!

[jeremyhu (Jeremy Huddleston Sequoia)]

r120130

[RJVB (René Bertin)]

The portfile would need to blacklist gcc-4.2 on OS X 10.6 ..