-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.
f031f3105a