chezscheme fails to build on 10.11

[ararslan]

• [x] Ran brew update and retried your prior step?
• [x] Ran brew doctor, fixed as many issues as possible and retried your prior step?
• [ ] Confirmed this is problem with specific formulae and not Homebrew/brew? If it's a general Homebrew/brew problem please file this issue at https://github.com/Homebrew/brew/issues/new

Bug reports:

Full Gist: https://gist.github.com/ararslan/21597dcac66032d8283f5944a6c1bbe6

The formula for Chez Scheme version 9.4 fails to build since _clock_gettime isn't found. My understanding is that this stems from my use of Xcode 8 on OS X 10.11, which defines certain symbols to be able to cross-compile for Sierra, but doesn't actually make them available on the local system. Cloning the Chez repository and building, manually setting -Wl,-no_weak_imports, works fine. Given that https://github.com/Homebrew/homebrew-core/issues/3727 has been implemented, I would have expected this to no longer be an issue. Isn't weak importing now disabled by default, at least on El Capitan, or is there something I'm missing?

Quick view of the failure:

[23:27:07] alex:~ $ brew install chezscheme
==> Using the sandbox
==> Downloading https://github.com/cisco/ChezScheme/archive/v9.4.tar.gz
Already downloaded: /Users/alex/Library/Caches/Homebrew/chezscheme-9.4.tar.gz
==> ./configure --installprefix=/usr/local/Cellar/chezscheme/9.4 --threads --installschemename=chez
==> make install
Last 15 lines from /Users/alex/Library/Logs/Homebrew/chezscheme/02.make:
dyld: Symbol not found: _clock_gettime
  Referenced from: /private/tmp/chezscheme-20170219-22209-4vcmnj/ChezScheme-9.4/ta6osx/s/../bin/ta6osx/scheme
  Expected in: /usr/lib/libSystem.B.dylib

/bin/sh: line 1: 23254 Done                    echo '(reset-handler abort)' '(base-exception-handler (lambda (c) (fresh-line) (display-condition c) (newline) (reset)))' '(keyboard-interrupt-handler (lambda () (display "interrupted---aborting\n") (reset)))' '(optimize-level 3)' '(debug-level 0)' '(generate-inspector-information #f)' '(subset-mode (quote system))' '(compile-file "cmacros.ss" "cmacros.so")'
     23255 Trace/BPT trap: 5       | ../bin/ta6osx/scheme -q
make[4]: *** [cmacros.so] Error 133
make[4]: *** Waiting for unfinished jobs....
/bin/sh: line 1: 23256 Done                    echo '(reset-handler abort)' '(base-exception-handler (lambda (c) (fresh-line) (display-condition c) (newline) (reset)))' '(keyboard-interrupt-handler (lambda () (display "interrupted---aborting\n") (reset)))' '(optimize-level 3)' '(debug-level 0)' '(generate-inspector-information #f)' '(collect-trip-bytes (expt 2 24))' '(collect-request-handler (lambda () (collect 0 1)))' '(collect 1 2)' '(compile-library "../nanopass/nanopass.ss" "nanopass.so")'
     23257 Trace/BPT trap: 5       | ../bin/ta6osx/scheme -q --libdirs "../nanopass::." --compile-imported-libraries
make[4]: *** [nanopass.so] Error 133
make[3]: *** [allx] Error 2
make[2]: *** [bootstrap] Error 2
make[1]: *** [build] Error 2
make: *** [install] Error 2

Thanks for your help!

[ilovezfs]

Closed via #10159.