[tlbuild] Latest sources on Macintosh

[Richard Koch]

This year we'll build on 10.11 (El Capitan) for 10.11, 10.12, 10.13. When the current sources are built on 10.11, the following error appears:

In file included from ../../../texk/web2c/xetexdir/XeTeXFontMgr_Mac.mm:42:
In file included from ../../../texk/web2c/xetexdir/XeTeXFontMgr_Mac.h:37:
In file included from ../../../texk/web2c/xetexdir/XeTeXFontMgr.h:47:
In file included from ../../../texk/web2c/xetexdir/XeTeX_ext.h:38:
In file included from /Users/koch/texlive2018dev/source/Work/libs/icu/include/unicode/utypes.h:38:
/Users/koch/texlive2018dev/source/Work/libs/icu/include/unicode/umachine.h:347:13: error: unknown type name 'char16_t'
    typedef char16_t UChar;
            ^
1 error generated.
make[5]: *** [xetexdir/libxetex_a-XeTeXFontMgr_Mac.o] Error 1
make[4]: *** [all-recursive] Error 1
make[3]: *** [all] Error 2
make[2]: *** [recurse] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all-recursive] Error 1

Apparently icu compiles fine, but then XeTeX runs into an error interpreting char16_t which it includes from the icu material. I'll look into this next week. If anyone has a hint, please send it to me.

Happily, the entire source tree compiles fine on 10.13, and passes all tests there.

Dick Koch
koch at uoregon.edu