The interesting section of the output seems to be:

gcc -DHAVE_CONFIG_H -I. -I.. -include libc-symbols.h -W -Wall -Wbad-function-cast -Wcast-align -Wcast-qual -Winline -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wshadow -Wstrict-prototypes -Wundef -Wpointer-arith -Werror -D_REENTRANT=1 -D_GNU_SOURCE -DPLUGINDIR="/nix/store/ryy6c7a732nv242c7qylw667n173g9qp-libxcrypt-3.0.2/lib/xcrypt" -g -O2 -c crypt-entry.c -fno-common -DPIC -o .libs/crypt-entry.o
In file included from xcrypt-private.h:11,
from crypt-entry.c:45:
xcrypt.h:23:22: error: features.h: No such file or directory
cc1: warnings being treated as errors
In file included from xcrypt-private.h:11,
from crypt-entry.c:45:

$ nix-env –version
nix-env (Nix) 0.16

$ nix-channel –list
http://nixos.org/releases/nixpkgs/channels/nixpkgs-unstable

$ gcc –version
i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5664)

Submitted by Cillian de Róiste on 26 November 2010 at 11:26