libassuan: passthru outputBin as `bin`

pkgs/by-name/li/libassuan/package.nix

···
   gitUpdater,
 }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "libassuan";
   version = "3.0.2";
 
   src = fetchurl {
-    url = "mirror://gnupg/libassuan/libassuan-${version}.tar.bz2";
+    url = "mirror://gnupg/libassuan/libassuan-${finalAttrs.version}.tar.bz2";
     hash = "sha256-0pMc2tJm5jNRD5lw4aLzRgVeNRuxn5t4kSR1uAdMNvY=";
   };
 
···
     "info"
   ];
   outputBin = "dev"; # libassuan-config
+  passthru.bin = finalAttrs.finalPackage.${finalAttrs.outputBin}; # fixes lib.getExe
 
   depsBuildBuild = [ buildPackages.stdenv.cc ];
   buildInputs = [
···
       provided.
     '';
     homepage = "https://gnupg.org/software/libassuan/";
-    changelog = "https://dev.gnupg.org/source/libassuan/browse/master/NEWS;libassuan-${version}";
+    changelog = "https://dev.gnupg.org/source/libassuan/browse/master/NEWS;libassuan-${finalAttrs.version}";
     license = lib.licenses.lgpl2Plus;
     platforms = lib.platforms.all;
     maintainers = [ ];
   };
-}
+})