comma: Fix cross

pkgs/by-name/co/comma/package.nix

···
 {
+  stdenv,
   comma,
   fetchFromGitHub,
   installShellFiles,
···
   nix,
   rustPlatform,
   testers,
+  buildPackages,
 }:
 
 rustPlatform.buildRustPackage rec {
···
       "$out/share/comma/command-not-found.nu" \
       "$out/share/comma/command-not-found.fish" \
       --replace-fail "comma --ask" "$out/bin/comma --ask"
-
-    "$out/bin/comma" --mangen > comma.1
+  ''
+  + lib.optionalString (stdenv.hostPlatform.emulatorAvailable buildPackages) ''
+    ${stdenv.hostPlatform.emulator buildPackages} "$out/bin/comma" --mangen > comma.1
     installManPage comma.1
   '';