iperf: broken on darwin

[acowley]

Issue description

iperf3 does not build on darwin

Steps to reproduce

Consult the hydra build log

Technical details

I think _mach_init_routine needs to be added to pkgs/os-specific/darwin/apple-source-releases/Libsystem/system_kernel_symbols but I have not tested this as it requires a lot of compiling.

• System: darwin
• Nix version: 1.11.4
• Nixpkgs version: "17.03pre-git"

[acowley]

A bit more detail on why I suggested what I did since I may well be misinterpreting something. On OS X 10.11.6

$ nm /usr/lib/libSystem.dylib | grep "_mach"
                 U __mach_fork_child
0000000000001b56 t _mach_init_old
00000000000022b0 D _mach_init_routine

And if, when building iperf3, I manually run the failing step with the addition of -L/usr/lib -lSystem, it links successfully.

[mitchty]

As a note, adding _mach_init_routine to the system_kernel_symbols gets iperf working again. No issues in anything else I use. I'll submit a PR tonight if I remember.

[LnL7]

adding the symbol to system_kernel_modules works by accident, I'm testing some changes that fix this properly.

[LnL7]

I pushed the fix to staging 16a9083