supercollider-with-plugins: fix plugin discovery

Assisted-by: Codex (GPT-6)

pkgs/development/interpreters/supercollider/default.nix

@@ -21,7 +21,6 @@
   gitUpdater,
   supercollider-with-plugins,
   supercolliderPlugins,
-  writeText,
   runCommand,
 }:
 
@@ -87,25 +86,29 @@ stdenv.mkDerivation rec {
     };
 
     tests = {
-      # test to make sure sclang runs and included plugins are successfully found
+      # Check both language classes and server UGens, without an audio device.
       sclang-sc3-plugins =
         let
           supercollider-with-test-plugins = supercollider-with-plugins.override {
             plugins = with supercolliderPlugins; [ sc3-plugins ];
           };
-          testsc = writeText "test.sc" ''
-            var err = 0;
-            try {
-            MdaPiano.name.postln;
-            } {
-            err = 1;
-            };
-            err.exit;
-          '';
         in
-        runCommand "sclang-sc3-plugins-test" { } ''
-          timeout 60s env XDG_CONFIG_HOME="$(mktemp -d)" QT_QPA_PLATFORM=minimal ${supercollider-with-test-plugins}/bin/sclang ${testsc} >$out
-        '';
+        runCommand "sclang-sc3-plugins-test"
+          {
+            QT_QPA_PLATFORM = "offscreen";
+          }
+          ''
+            export XDG_CONFIG_HOME="$TMPDIR/config"
+            export XDG_DATA_HOME="$TMPDIR/data"
+            export XDG_CACHE_HOME="$TMPDIR/cache"
+            mkdir -p "$out"
+            timeout 60s ${supercollider-with-test-plugins}/bin/sclang \
+              ${./tests/sc3-plugins.scd} "$out" 2>&1 | tee "$out/log"
+            grep -Fq 'SC3 plugins rendered successfully' "$out/log"
+            if grep -E 'ERROR|FAILURE|duplicate' "$out/log"; then
+              exit 1
+            fi
+          '';
     };
   };
 

pkgs/development/interpreters/supercollider/tests/sc3-plugins.scd

@@ -0,0 +1,58 @@
+var output = thisProcess.argv[0];
+var definition, score;
+
+try {
+    // Resolve symbols at runtime: an undefined class literal prevents the entire
+    // script (including its error handler and exit) from being compiled.
+    [\MembraneHexagon, \MdaPiano].do { |name|
+        if(name.asClass.isNil) {
+            Error("Missing SC3 class: " ++ name).throw;
+        };
+    };
+
+    definition = SynthDef(\sc3PluginsTest, {
+        // Give each UGen its own output channel so neither can mask a failure.
+        Out.ar(0, \MembraneHexagon.asClass.ar(Impulse.ar(0)));
+        Out.ar(1, \MdaPiano.asClass.ar.sum);
+    });
+    score = Score([
+        [0, [\d_recv, definition.asBytes]],
+        [0, [\s_new, definition.name, 1000, 0, 0]],
+        [1, [\n_free, 1000]]
+    ]);
+
+    score.recordNRT(
+        oscFilePath: output +/+ "score.osc",
+        outputFilePath: output +/+ "sc3.wav",
+        headerFormat: "WAV",
+        sampleFormat: "float",
+        options: ServerOptions.new.numInputBusChannels_(0).numOutputBusChannels_(2),
+        action: { |exitCode|
+            var file, samples;
+            try {
+                if(exitCode != 0) { Error("scsynth exited with " ++ exitCode).throw };
+                file = SoundFile.openRead(output +/+ "sc3.wav");
+                if(file.isNil) { Error("No rendered audio").throw };
+                if(file.numChannels != 2) { Error("Expected two audio channels").throw };
+                if(file.numFrames < 44100) { Error("Incomplete rendered audio").throw };
+                samples = FloatArray.newClear(file.numFrames * file.numChannels);
+                file.readData(samples);
+                file.close;
+                samples.clump(2).flop.do { |channel|
+                    if(channel.any { |sample| sample.isNaN or: { sample.abs == inf } }) {
+                        Error("Invalid SC3 UGen output").throw;
+                    };
+                    if(channel.abs.maxItem <= 0.00001) { Error("Silent SC3 UGen output").throw };
+                };
+                "SC3 plugins rendered successfully".postln;
+                0.exit;
+            } { |error|
+                error.reportError;
+                1.exit;
+            };
+        }
+    );
+} { |error|
+    error.reportError;
+    1.exit;
+};

pkgs/development/interpreters/supercollider/wrapper.nix

@@ -1,4 +1,5 @@
 {
+  lib,
   symlinkJoin,
   makeWrapper,
   supercollider,
@@ -12,10 +13,19 @@ symlinkJoin {
   nativeBuildInputs = [ makeWrapper ];
 
   postBuild = ''
+    # --include-path adds to the paths from the user's language configuration,
+    # including an explicit -l configuration (as used by tidal-cycles-full).
+    if [ -d "$out/share/SuperCollider/Extensions" ]; then
+      wrapProgram "$out/bin/sclang" \
+        --add-flags "--include-path $out/share/SuperCollider/Extensions"
+    fi
+
     for exe in $out/bin/*; do
-      wrapProgram $exe \
-        --set SC_PLUGIN_DIR "$out/lib/SuperCollider/plugins" \
-        --set SC_DATA_DIR   "$out/share/SuperCollider"
+      # scide launches sclang, and sclang launches scsynth, through PATH.
+      # The server already loads its core UGens from its compiled-in path.
+      wrapProgram "$exe" \
+        --prefix PATH : "$out/bin" \
+        --prefix SC_PLUGIN_PATH : "${lib.makeSearchPath "lib/SuperCollider/plugins" plugins}"
     done
   '';