Link against mimalloc by overriding stdenv

flake.nix

@@ -98,7 +98,10 @@
         localSystem = builtins.currentSystem or platform;
         crossSystem = platform;
         overlays = [ self.overlays.default ];
-        config.allowUnsupportedSystem = true;
+        config = {
+          allowUnsupportedSystem = true;
+          replaceStdenv = { pkgs }: self.lib.stdenv pkgs;
+        };
       });
 
     packages = eachSystem (system: platform:

lib/stdenv.nix

@@ -0,0 +1,23 @@
+{ ... }: pkgs:
+
+let
+  inherit (pkgs) lib;
+  inherit (lib) optionalAttrs toList;
+
+  ldflags = [ "-lmimalloc" ];
+  rustflags = map (flag: [ "-C" "link-arg=${flag}" ]) ldflags |> lib.flatten;
+
+  exclude = lib.genAttrs [
+    "mimalloc"
+    "perl"
+  ] (pkg: null);
+in pkgs.addAttrsToDerivation (prevAttrs: optionalAttrs (!exclude ? ${lib.getName prevAttrs}) ({
+  buildInputs = prevAttrs.buildInputs or [ ] ++ [ pkgs.mimalloc ];
+  env = prevAttrs.env or { } // optionalAttrs (prevAttrs ? env.NIX_LDFLAGS) {
+    NIX_LDFLAGS = toList prevAttrs.NIX_LDFLAGS or [ ] ++ ldflags |> toString;
+  };
+
+  NIX_RUSTFLAGS = prevAttrs.NIX_RUSTFLAGS or [ ] ++ rustflags;
+} // optionalAttrs (!prevAttrs ? env.NIX_LDFLAGS) {
+  NIX_LDFLAGS = toList prevAttrs.NIX_LDFLAGS or [ ] ++ ldflags;
+})) pkgs.stdenv

overlay/mimalloc.nix

@@ -33,10 +33,6 @@ in {
 
   fractal = prev.fractal.overrideAttrs (prevAttrs: {
     nativeBuildInputs = prevAttrs.nativeBuildInputs or [ ] ++ [ final.makeBinaryWrapper ];
-    buildInputs = prevAttrs.buildInputs or [ ] ++ [ final.mimalloc ];
-
-    NIX_RUSTFLAGS = lib.toList prevAttrs.NIX_RUSTFLAGS or [ ] ++ [ "-C" "link-arg=-lmimalloc" ];
-    
     postInstall = prevAttrs.postInstall or "" + ''
       wrapProgram "$out/bin/fractal" \
         --set MIMALLOC_RESERVE_HUGE_OS_PAGES 1
@@ -47,47 +43,4 @@ in {
     mpv = final.mpv-unwrapped;
     extraMakeWrapperArgs = [ "--set" "MIMALLOC_RESERVE_HUGE_OS_PAGES" "1" ];
   };
-} // lib.genAttrs [
+}
-  "bat"
-  "bottom"
-  "cryptsetup"
-  "dbus-broker"
-  "erlang"
-  "fd"
-  "firefox-unwrapped"
-  "fuzzel"
-  "helix"
-  "kitty"
-  "mako"
-  "mpv-unwrapped"
-  "niri"
-  "nix"
-  "nushell"
-  "openssh"
-  "pipewire"
-  "pueue"
-  "ripgrep"
-  "sd"
-  "sioyek"
-  "sudo-rs"
-  "systemd"
-  "swayidle"
-  "swaylock"
-  "swaylock-effects"
-  "thunderbird-unwrapped"
-  "uutils-coreutils"
-  "uutils-coreutils-noprefix"
-  "waybar"
-  "wirepluber"
-  "xdg-desktop-portal-gnome"
-  "xdg-desktop-portal-gtk"
-] (pkg: prev.${pkg}.overrideAttrs (prevAttrs: {
-  buildInputs = prevAttrs.buildInputs or [ ] ++ [ final.mimalloc ];
-  env = prevAttrs.env or { } // lib.optionalAttrs (prevAttrs ? env.NIX_LDFLAGS) {
-    NIX_LDFLAGS = toString (lib.toList prevAttrs.env.NIX_LDFLAGS or [ ] ++ [ "-lmimalloc" ]);
-  };
-
-  NIX_RUSTFLAGS = lib.toList prevAttrs.NIX_RUSTFLAGS or [ ] ++ [ "-C" "link-arg=-lmimalloc" ];
-} // lib.optionalAttrs (!prevAttrs ? env.NIX_LDFLAGS) {
-  NIX_LDFLAGS = lib.toList prevAttrs.NIX_LDFLAGS or [ ] ++ [ "-lmimalloc" ];
-}))