-split-sections replaced -split-objs with following upsides:
1) -split-objs adds considerable overhead to compile time
2) combined with stripping, it causes issues when cross-compiling
For upstream see https://ghc.haskell.org/trac/ghc/ticket/8405
This is supported only for Linux/Windows using ld linker.
GHC master also turns on -split-sections by default.
Example using stack:
Without splitting
$ du /nix/store/5paayhibayr73zqfaj458g4k4mv108jn-stack-1.3.2
4 /nix/store/5paayhibayr73zqfaj458g4k4mv108jn-stack-1.3.2/share/bash-completion/completions
4 /nix/store/5paayhibayr73zqfaj458g4k4mv108jn-stack-1.3.2/share/bash-completion
4 /nix/store/5paayhibayr73zqfaj458g4k4mv108jn-stack-1.3.2/share
23416 /nix/store/5paayhibayr73zqfaj458g4k4mv108jn-stack-1.3.2/bin
23420 /nix/store/5paayhibayr73zqfaj458g4k4mv108jn-stack-1.3.2
With -split-objs
$ du /nix/store/fypymm529adpx71gdzm0851xz42wdbz0-stack-1.3.2
20632 /nix/store/fypymm529adpx71gdzm0851xz42wdbz0-stack-1.3.2/bin
4 /nix/store/fypymm529adpx71gdzm0851xz42wdbz0-stack-1.3.2/share/bash-completion/completions
4 /nix/store/fypymm529adpx71gdzm0851xz42wdbz0-stack-1.3.2/share/bash-completion
4 /nix/store/fypymm529adpx71gdzm0851xz42wdbz0-stack-1.3.2/share
20636 /nix/store/fypymm529adpx71gdzm0851xz42wdbz0-stack-1.3.2
With -split-sections
$ du /nix/store/40l6krinx1zx41lr87c4m12hxj4ldf3x-stack-1.3.2
4 /nix/store/40l6krinx1zx41lr87c4m12hxj4ldf3x-stack-1.3.2/share/bash-completion/completions
4 /nix/store/40l6krinx1zx41lr87c4m12hxj4ldf3x-stack-1.3.2/share/bash-completion
4 /nix/store/40l6krinx1zx41lr87c4m12hxj4ldf3x-stack-1.3.2/share
20672 /nix/store/40l6krinx1zx41lr87c4m12hxj4ldf3x-stack-1.3.2/bin
20676 /nix/store/40l6krinx1zx41lr87c4m12hxj4ldf3x-stack-1.3.2
Note: you currently need following overrides to build stack on 802:
vector-algorithms = dontCheck super.vector-algorithms;
path-io = doJailbreak super.path-io;
stack = doJailbreak super.stack;
Note: Should also work on GHC 8.0.1, but I'm being careful here.
We could backport later on.
The callCabal2nix function cannot reliably determine the appropriate "name" for
the package it's processing. Attempts to derive this information have led to
plenty of evaluation errors, and so I'd like to go for the obvious and reliable
solution now and let the caller specify that bit of information.
Here is an example that demonstrates how to use callCabal2nix.
let
pkgs = import <nixpkgs> {};
src = pkgs.fetchFromGitHub {
owner = "gtk2hs";
repo = "gtk2hs";
rev = "eee61d84edf1dd44f8d380d7d7cae2405de50124";
sha256 = "12i53grimni0dyjqjydl120z5amcn668w4pfhl8dxscjh4a0l5nb";
};
in
pkgs.haskellPackages.callCabal2nix "gtkhs-tools" "${src}/tools" {}
