reduce runtime closure size

[tomberek]

Currently the runtime closure of the rfc101 branch includes ghc-9 references. This creates a 2GB+ runtime closure. It seems this is for the library outputs.

The below fixes this, but we may instead want to do multiple outputs or use another approach to remove these.

diff --git a/flake.nix b/flake.nix
index 83661b5..231cadc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -25,6 +25,13 @@
           haskell = super.haskell // {
             packageOverrides = self: super: {
               nixfmt = self.callCabal2nix "nixfmt" src { };
+              nixfmt-bin = self.nixfmt.overrideAttrs (old: {
+                disallowedRequisites = [ self.ghc ];
+                postFixup = ''
+                  rm -rf $out/lib
+                  rm -rf $out/nix-support
+                  '';
+              });
             };
           };
         };
@@ -68,6 +75,7 @@
         packages = rec {
           default = nixfmt;
           nixfmt = pkgs.haskellPackages.nixfmt;
+          nixfmt-bin = pkgs.haskellPackages.nixfmt-bin;
           nixfmt-static = haskell.lib.justStaticExecutables nixfmt;
           nixfmt-deriver = nixfmt-static.cabal2nixDeriver;
           nixfmt-js = ghcjsPackages.callCabal2nix "nixfmt" src { };

Note: there are some cabal2nix issues regarding this already

[SuperSandro2000]

This probably just requires a wrapping with justStaticExecutables

[infinisil]

Indeed, and this is already the case for the nixfmt-static attribute. Could be made the default though.