Hack to fix libc++abi build

Changed files
+1
pkgs
development
libraries
libc++abi
+1
pkgs/development/libraries/libc++abi/default.nix
···
# Hack: NIX_CFLAGS_COMPILE doesn't work here because clang++ isn't
# wrapped at this point.
export CXX="clang++ -D_LIBCXX_DYNAMIC_FALLBACK=1"
'';
installPhase = if stdenv.isDarwin
···
# Hack: NIX_CFLAGS_COMPILE doesn't work here because clang++ isn't
# wrapped at this point.
export CXX="clang++ -D_LIBCXX_DYNAMIC_FALLBACK=1"
+
unset SDKROOT
'';
installPhase = if stdenv.isDarwin