Merge pull request #324071 from tie/emulator-exec

lib/systems: use execline’s exec instead of runtimeShell

lib/systems/default.nix

@@ -298,8 +298,11 @@ let
             };
             wine = (pkgs.winePackagesFor "wine${toString final.parsed.cpu.bits}").minimal;
           in
+          # Note: we guarantee that the return value is either `null` or a path
+          # to an emulator program. That is, if an emulator requires additional
+          # arguments, a wrapper should be used.
           if pkgs.stdenv.hostPlatform.canExecute final
-          then "${pkgs.runtimeShell} -c '\"$@\"' --"
+          then "${pkgs.execline}/bin/exec"
           else if final.isWindows
           then "${wine}/bin/wine${optionalString (final.parsed.cpu.bits == 64) "64"}"
           else if final.isLinux && pkgs.stdenv.hostPlatform.isLinux && final.qemuArch != null