adjust postInstall hook

default.nix

@@ -34,6 +34,8 @@ let
     stdenv = crossPkgs.stdenv;
     apple-sdk = if hostPlatform.isx86_64 then crossPkgs.apple-sdk_13 else crossPkgs.apple-sdk_14;
     installShellFiles = crossPkgs.installShellFiles;
+    installShellCompletions = false;
+    installManPages = false;
     notmuch = crossPkgs.notmuch;
     gpgme = crossPkgs.gpgme;
     pkg-config = crossPkgs.pkg-config;
@@ -48,8 +50,6 @@ himalaya.overrideAttrs (drv: {
   propagatedBuildInputs = (drv.propagatedBuildInputs or [ ])
     ++ lib.optional hostPlatform.isWindows empty-libgcc_eh;
 
-  postInstall = null;
-
   src = crossPkgs.nix-gitignore.gitignoreSource [ ] ./.;
 
   cargoDeps = rustPlatform.importCargoLock {

package.nix

@@ -42,23 +42,19 @@ rustPlatform.buildRustPackage rec {
   # unit tests only
   cargoTestFlags = [ "--lib" ];
 
-  preInstall = ''
-    mkdir -p $out/share/applications
+  postInstall = ''
+    mkdir -p $out/share/{applications,completions,man}
     cp assets/himalaya.desktop "$out"/share/applications/
-  '' + lib.optionalString installManPages ''
-    mkdir -p "$out"/share/man
+  '' + lib.optionalString stdenv.buildPlatform.canExecute stdenv.hostPlatform ''
     "$out"/bin/himalaya man "$out"/share/man
-  '' + lib.optionalString installShellCompletions ''
-    mkdir -p "$out"/share/completions
+  '' + lib.optionalString installManPages ''
+    installManPage "$out"/share/man/*
+  '' + lib.optionalString stdenv.buildPlatform.canExecute stdenv.hostPlatform ''
     "$out"/bin/himalaya completion bash > "$out"/share/completions/himalaya.bash
     "$out"/bin/himalaya completion elvish > "$out"/share/completions/himalaya.elvish
     "$out"/bin/himalaya completion fish > "$out"/share/completions/himalaya.fish
     "$out"/bin/himalaya completion powershell > "$out"/share/completions/himalaya.powershell
     "$out"/bin/himalaya completion zsh > "$out"/share/completions/himalaya.zsh
-  '';
-
-  postInstall = lib.optionalString installManPages ''
-    installManPage "$out"/share/man/*
   '' + lib.optionalString installShellCompletions ''
     installShellCompletion "$out"/share/completions/himalaya.{bash,fish,zsh}
   '';