flake::dolphin-emu: correctly set DOLPHIN_WC_REVISION in order to mak…

…e netplay usable in my configuration

It is not possible to use git describe in a pure system like Nix which hashes all inputs, (since the git index changes whenever anybody pushes a branch, etc), so I have set DOLPHIN_WC_DESCRIBE to the first 8 chars of the scm revision instead of the usual expected value since I have no way of retrieving it. Until dolphin-emu/dolphin#9898 is merged I will be unable to use the Netplay browser, but the scm revision is enough to join Netplay sessions.

flake.nix

@@ -29,7 +29,7 @@
     # Declare some local packages be available via self.packages
     packages.x86_64-linux = let pkgs = import nixpkgs { system = "x86_64-linux"; config.allowUnfree = true; }; in {
       parsecgaming = pkgs.callPackage ./pkgs/parsecgaming {};
-      dolphin-emu = pkgs.dolphinEmuMaster.overrideAttrs (oa: { src = inputs.dolphin-emu; version = inputs.dolphin-emu.rev; cmakeFlags = [ "-DUSE_SHARED_ENET=ON" "-DENABLE_LTO=ON" "-DDOLPHIN_WC_BRANCH=master" ]; });
+      dolphin-emu = pkgs.dolphinEmuMaster.overrideAttrs (old: { src = inputs.dolphin-emu; version = inputs.dolphin-emu.rev; cmakeFlags = old.cmakeFlags ++ [ "-DDOLPHIN_WC_REVISION=${inputs.dolphin-emu.rev}" "-DDOLPHIN_WC_DESCRIBE=${pkgs.lib.substring 0 8 inputs.dolphin-emu.rev}" ]; });
     };
 
     robotnixConfigurations = nixpkgs.lib.mapAttrs (n: v: inputs.robotnix.lib.robotnixSystem v) {