speechd: Fix espeak-mbrola voice check

pkgs/applications/audio/espeak-ng/default.nix

@@ -45,6 +45,10 @@ stdenv.mkDerivation rec {
     patchelf --set-rpath "$(patchelf --print-rpath $out/bin/espeak-ng)" $out/bin/speak-ng
   '';
 
+  passthru = {
+    inherit mbrolaSupport;
+  };
+
   meta = with lib; {
     description = "Open source speech synthesizer that supports over 70 languages, based on eSpeak";
     homepage = "https://github.com/espeak-ng/espeak-ng";

pkgs/development/libraries/speechd/default.nix

@@ -19,6 +19,7 @@
 , withOss ? false
 , withFlite ? true, flite
 , withEspeak ? true, espeak, sonic, pcaudiolib
+, mbrola
 , withPico ? true, svox
 }:
 
@@ -38,6 +39,12 @@ in stdenv.mkDerivation rec {
       src = ./fix-paths.patch;
       utillinux = util-linux;
     })
+  ] ++ lib.optionals espeak.mbrolaSupport [
+    # Replace FHS paths.
+    (substituteAll {
+      src = ./fix-mbrola-paths.patch;
+      inherit espeak mbrola;
+    })
   ];
 
   nativeBuildInputs = [

pkgs/development/libraries/speechd/fix-mbrola-paths.patch

@@ -0,0 +1,21 @@
+diff --git a/src/modules/espeak.c b/src/modules/espeak.c
+index 94a01197..9bb34475 100644
+--- a/src/modules/espeak.c
++++ b/src/modules/espeak.c
+@@ -898,13 +898,13 @@ static SPDVoice **espeak_list_synthesis_voices()
+ 				path = g_strdup_printf("%s/mbrola/%s", espeak_data, voicename);
+ 				if (access(path, O_RDONLY) != 0) {
+ 					g_free(path);
+-					path = g_strdup_printf("/usr/share/mbrola/%s", voicename);
++					path = g_strdup_printf("@mbrola@/share/mbrola/%s", voicename);
+ 					if (access(path, O_RDONLY) != 0) {
+ 						g_free(path);
+-						path = g_strdup_printf("/usr/share/mbrola/%s/%s", voicename, voicename);
++						path = g_strdup_printf("@mbrola@/share/mbrola/%s/%s", voicename, voicename);
+ 						if (access(path, O_RDONLY) != 0) {
+ 							g_free(path);
+-							path = g_strdup_printf("/usr/share/mbrola/voices/%s", voicename);
++							path = g_strdup_printf("@mbrola@/share/mbrola/voices/%s", voicename);
+ 							if (access(path, O_RDONLY) != 0) {
+ 								g_free(path);
+ 								espeak_mbrola[j] = NULL;