darwin: c compiler cannot create executables

[matthewbauer]

Hi,

The build on Hydra for nix-exec has been broken for a while:

https://hydra.nixos.org/build/64065685

Here is the log:

unpacking sources
unpacking source archive /nix/store/rp1j1lwd3gpw7daks18as98pkjzkdgrx-nix-exec-4.1.6.tar.xz
source root is nix-exec-4.1.6
setting SOURCE_DATE_EPOCH to timestamp 1485881901 of file nix-exec-4.1.6/missing
patching sources
configuring
fixing libtool script ./ltmain.sh
configure flags: --disable-static --disable-dependency-tracking --prefix=/nix/store/mdyn2ykj9v4ysp4cryrvnkzc9i83zq3m-nix-exec-4.1.6
checking for a BSD-compatible install... /nix/store/s4sagzgijfbil29dgyxcv24pip8na49k-coreutils-8.28/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /nix/store/s4sagzgijfbil29dgyxcv24pip8na49k-coreutils-8.28/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking for style of include used by make... GNU
checking for gcc... clang
checking whether the C compiler works... no
configure: error: in `/private/tmp/nix-build-nix-exec-4.1.6.drv-0/nix-exec-4.1.6':
configure: error: C compiler cannot create executables
See `config.log' for more details
builder for ‘/nix/store/shnvlfrmqymhr06i612i898nivqxqwg4-nix-exec-4.1.6.drv’ failed with exit code 77

Not sure what test is failing here, but maybe it can be disabled?

[shlevy]

This definitely isn't a test that can be skipped, but I have no idea why this would be getting triggered. The build is broken on Linux anyway though, so when I get around to fixing that I'll also get this fixed.