diff --git a/.github/scripts/run-zephyr-tests.sh b/.github/scripts/run-zephyr-tests.sh
index 20dddda94c..d1c1d1c4e9 100755
--- a/.github/scripts/run-zephyr-tests.sh
+++ b/.github/scripts/run-zephyr-tests.sh
@@ -1,15 +1,7 @@
 #!/bin/bash
-timeout=300 # 5min timeout is hopefully enough
-verbose=false
 
-# Function to recursively find all folders containing the top-level CMakeLists.txt
-overall_success=true
-num_successes=0
-num_failures=0
-failed_tests=""
-
-# Skip tests doing file IO and tracing
-skip=("FileReader" "FilePkgReader" "Tracing" "ThreadedThreaded" "CountTest" "AsyncCallback")
+# Skip
+skip=("FileReader" "FilePkgReader")
 
 find_kconfig_folders() {
     if [ -f "$folder/CMakeLists.txt" ]; then
@@ -20,17 +12,15 @@ find_kconfig_folders() {
             echo "Skipping: $test_name"
         else
             echo "Running: $test_name"
-            if run_qemu_zephyr_test "$folder"; then
-                echo "Test $test_name successful"
+            run_qemu_zephyr_test $folder
+            if [ "$?" -eq 0 ]; then
+                echo "Test passed"
                 let "num_successes+=1"
             else
-                echo "Test $test_name failed"
-                let "num_failures+=1"
-                failed_tests+="$test_name, "
-                overall_success=false
+                echo "Test failed."
+                exit 1
             fi
         fi
-
       return
     fi
     for folder in "$1"/*; do
@@ -40,88 +30,55 @@ find_kconfig_folders() {
     done
 }
 
-run_native_zephyr_test() {
-    return_val=0
-    pushd $1/build
-
-    rm -f res.text
-
-    timeout 60s make run | tee res.txt
-    result=$?
-
-    if [ $result -eq 0 ]; then
-        echo "Command completed within the timeout."
-        return_val=0
-    else
-        echo "Command terminated or timed out."
-        echo "Test output:"
-        echo "----------------------------------------------------------------"
-        cat res.txt
-        echo "----------------------------------------------------------------"
-        return_val=1
-    fi
-
-    popd
-    return "$return_val"
-
-
-
-
-}
-
-# Run Zephyr test until either: Timeout or finds match in output
-# https://www.unix.com/shell-programming-and-scripting/171401-kill-process-if-grep-match-found.html
+# Run Zephyr test until either: Timeout or finds match in output using expect
+# https://spin.atomicobject.com/monitoring-stdout-with-a-timeout/
 run_qemu_zephyr_test() {
     success=false
     pushd $1/build
-
-    rm -f /tmp/procfifo
-    rm -f res.text
-    mkfifo /tmp/procfifo
-
-    make run | tee res.txt >  /tmp/procfifo &
-    PID=$!
-    SECONDS=0
-    while IFS= read -t $timeout line
-    do
-        if [ "$verbose" = "true" ]; then  echo $line; fi
-
-        if echo "$line" | grep -q 'FATAL ERROR';
+    res="_res.txt"
+    # Run test program in background and pipe results to a file.
+    make run > $res &
+    if [ $? -ne 0 ]; then
+        echo "ERROR: make run failed."
+        exit 1
+    fi
+    pid=$!
+    return_val=2
+    wait_count=0
+    timeout=60
+    # Parse the file and match on known outputs. With timeout.
+    while [ "$wait_count" -le "$timeout" ]; do
+        sleep 1
+        if grep --quiet 'FATAL ERROR' "$res"
         then
-            echo "Matched on ERROR"
-            echo $line
-            success=false
-            pkill -P $$
+            cat $res
+            echo "-----------------------------------------------------------------------------------------------------------"
+            echo "ERROR: Found 'FATAL ERROR'"
+            return_val=1
             break
         fi
-
-        if echo "$line" | grep -q '^exit';
+        if grep --quiet '^exit' "$res"
         then
-                echo "Matched on exit"
-                success=true
-                pkill -P $$
-                break
-        fi
-
-        if (($SECONDS > $timeout)) ; then
-            echo "Timeout without freeze"
-            success=false
+            cat $res
+            echo "-----------------------------------------------------------------------------------------------------------"
+            echo "SUCCESS: Found 'exit'"
+            return_val=0
             break
         fi
-    done < /tmp/procfifo
 
-    return_val=0
-    if [ "$success" = false ]; then
-        echo "General Timeout"
-        pkill -P $$
-        echo "Test output:"
-        echo "----------------------------------------------------------------"
-        cat res.txt
-        echo "----------------------------------------------------------------"
-        return_val=1
+        ((wait_count++))
+    done
+    kill $pid
+    if [ $? -ne 0 ]; then
+        echo "ERROR: Could not kill qemu process"
+        exit 1
     fi
 
-    rm -f /tmp/procfifo
+    if [ "$return_val" -eq 2 ]; then
+        cat $res
+        echo "-----------------------------------------------------------------------------------------------------------"
+        echo "ERROR: Timed out"
+    fi
     popd
     return "$return_val"
 }
@@ -137,14 +94,8 @@ cd -
 
 # Print report
 echo "================================================================================================================"
-
-if [ "$overall_success" = false ]; then
-    echo "Results: FAIL"
-else
-    echo "Results: PASS"
-fi
+echo "Tests passed!"
 echo "Number of passes: $num_successes"
-echo "Number of fails: $num_failures"
 echo "Skipped tests: ${skip[@]}"
 
 if [ "$overall_success" = false ]; then
diff --git a/.github/workflows/custom-build.yml b/.github/workflows/custom-build.yml
new file mode 100644
index 0000000000..9f63be882f
--- /dev/null
+++ b/.github/workflows/custom-build.yml
@@ -0,0 +1,43 @@
+name: Custom build
+
+# Trigger the workflow every day at 5 AM (UTC).
+on:
+  workflow_dispatch:
+
+jobs:
+  custom-build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out lingua-franca repository
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+          fetch-depth: 0
+      - name: Prepare build environment
+        uses: ./.github/actions/prepare-build-env
+      - name: Modify property file to contain the commit SHA
+        shell: bash
+        run: |
+          TIMESTAMP="$(date +'%Y-%m-%d')"
+          SHA="$(git rev-parse --short HEAD)"
+          sed --regexp-extended --in-place "s/^(VERSION = .*)$/\1 ${SHA} ${TIMESTAMP}/" core/src/main/resources/org/lflang/StringsBundle.properties
+      - name: Build and package lf cli tools (nightly build)
+        shell: bash
+        run: |
+          export TIMESTAMP="$(date +'%Y%m%d%H%M%S')"
+          echo "timestamp=$TIMESTAMP" >> "$GITHUB_ENV"
+          ./gradlew build -Pnightly=$TIMESTAMP -PtargetOS=Linux -PtargetArch=x86_64
+          ./gradlew assemble -Pnightly=$TIMESTAMP -PtargetOS=Linux -PtargetArch=aarch64
+          ./gradlew assemble -Pnightly=$TIMESTAMP -PtargetOS=MacOS -PtargetArch=x86_64
+          ./gradlew assemble -Pnightly=$TIMESTAMP -PtargetOS=MacOS -PtargetArch=aarch64
+          ./gradlew assemble -Pnightly=$TIMESTAMP -PtargetOS=Windows -PtargetArch=x86_64
+      - name: Deploy nightly release
+        uses: marvinpinto/action-automatic-releases@latest
+        with:
+          repo_token: "${{ secrets.NIGHTLY_BUILD }}"
+          automatic_release_tag: '${{ github.ref_name }}'
+          prerelease: true
+          draft: true
+          title: "Custom Lingua Franca build for ${{ github.ref_name }} branch"
+          files: |
+            build/distributions/*
diff --git a/core/src/main/java/org/lflang/MessageReporterBase.java b/core/src/main/java/org/lflang/MessageReporterBase.java
index edd39d2799..287d47153f 100644
--- a/core/src/main/java/org/lflang/MessageReporterBase.java
+++ b/core/src/main/java/org/lflang/MessageReporterBase.java
@@ -40,11 +40,17 @@ public Stage2 at(Path file, Range range) {
 
   @Override
   public Stage2 at(EObject node) {
+    if (node == null) {
+      return nowhere();
+    }
     return wrap((severity, message) -> reportOnNode(node, severity, message));
   }
 
   @Override
   public Stage2 at(EObject node, EStructuralFeature feature) {
+    if (node == null) {
+      return nowhere();
+    }
     return wrap((severity, message) -> reportOnNode(node, feature, severity, message));
   }
 
diff --git a/core/src/main/java/org/lflang/federated/extensions/CExtensionUtils.java b/core/src/main/java/org/lflang/federated/extensions/CExtensionUtils.java
index fb74f98c1a..4b1fed0afe 100644
--- a/core/src/main/java/org/lflang/federated/extensions/CExtensionUtils.java
+++ b/core/src/main/java/org/lflang/federated/extensions/CExtensionUtils.java
@@ -201,6 +201,7 @@ public static void handleCompileDefinitions(
     }
     definitions.put("NUMBER_OF_FEDERATES", String.valueOf(numOfFederates));
     definitions.put("EXECUTABLE_PREAMBLE", "");
+    definitions.put("FEDERATE_ID", String.valueOf(federate.id));
 
     CompileDefinitionsProperty.INSTANCE.update(federate.targetConfig, definitions);
 
@@ -303,7 +304,8 @@ public static void generateCMakeInclude(
         "add_compile_definitions(LF_SOURCE_DIRECTORY=\"" + fileConfig.srcPath + "\")");
     cmakeIncludeCode.pr(
         "add_compile_definitions(LF_PACKAGE_DIRECTORY=\"" + fileConfig.srcPkgPath + "\")");
-
+    cmakeIncludeCode.pr(
+        "add_compile_definitions(LF_SOURCE_GEN_DIRECTORY=\"" + fileConfig.getSrcGenPath() + "\")");
     try (var srcWriter = Files.newBufferedWriter(cmakeIncludePath)) {
       srcWriter.write(cmakeIncludeCode.getCode());
     }
diff --git a/core/src/main/java/org/lflang/federated/launcher/FedLauncherGenerator.java b/core/src/main/java/org/lflang/federated/launcher/FedLauncherGenerator.java
index 5ec59ecb34..67cc8085f0 100644
--- a/core/src/main/java/org/lflang/federated/launcher/FedLauncherGenerator.java
+++ b/core/src/main/java/org/lflang/federated/launcher/FedLauncherGenerator.java
@@ -124,7 +124,7 @@ public void doGenerate(List<FederateInstance> federates, RtiConfig rtiConfig) {
       target = user + "@" + host;
     }
 
-    shCode.append("#### Host is ").append(host);
+    shCode.append("#### Host is ").append(host).append("\n");
 
     // Launch the RTI in the foreground.
     if (host.equals("localhost") || host.equals("0.0.0.0")) {
diff --git a/core/src/main/java/org/lflang/generator/CodeBuilder.java b/core/src/main/java/org/lflang/generator/CodeBuilder.java
index 9fe82e46fd..af82d70512 100644
--- a/core/src/main/java/org/lflang/generator/CodeBuilder.java
+++ b/core/src/main/java/org/lflang/generator/CodeBuilder.java
@@ -126,7 +126,8 @@ public void prSourceLineNumber(EObject eObject, boolean suppress) {
         }
       }
       // Extract the filename from eResource, an astonishingly difficult thing to do.
-      String filePath = CommonPlugin.resolve(eObject.eResource().getURI()).path();
+      String filePath =
+          CommonPlugin.resolve(eObject.eResource().getURI()).path().replace("\\", "\\\\");
       pr("#line " + (node.getStartLine() + offset) + " \"" + filePath + "\"");
     }
   }
@@ -558,7 +559,11 @@ public CodeMap writeToFile(String path) throws IOException {
     for (var line : (Iterable<String>) () -> s.lines().iterator()) {
       lineNumber++;
       if (line.contains(END_SOURCE_LINE_NUMBER_TAG) && !path.endsWith(".ino")) {
-        out.append("#line ").append(lineNumber).append(" \"").append(path).append("\"");
+        out.append("#line ")
+            .append(lineNumber)
+            .append(" \"")
+            .append(path.replace("\\", "\\\\"))
+            .append("\"");
       } else {
         out.append(line);
       }
diff --git a/core/src/main/java/org/lflang/generator/c/CCmakeGenerator.java b/core/src/main/java/org/lflang/generator/c/CCmakeGenerator.java
index 1390fa3ce0..7212e448a4 100644
--- a/core/src/main/java/org/lflang/generator/c/CCmakeGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CCmakeGenerator.java
@@ -422,6 +422,14 @@ CodeBuilder generateCMakeCode(
     }
     cMakeCode.newLine();
 
+    // Add definition of directory where the main CMakeLists.txt file resides because this is where
+    // any files specified by the `file` target directive will be put.
+    cMakeCode.pr(
+        "# Define directory in which files from the 'files' target directive will be put.");
+    cMakeCode.pr(
+        "target_compile_definitions(${LF_MAIN_TARGET} PUBLIC"
+            + " LF_TARGET_FILES_DIRECTORY=\"${CMAKE_CURRENT_LIST_DIR}\")");
+
     cMakeCode.pr(cMakeExtras);
     cMakeCode.newLine();
 
diff --git a/core/src/main/java/org/lflang/generator/c/CCompiler.java b/core/src/main/java/org/lflang/generator/c/CCompiler.java
index b26e7686e2..c0401b5684 100644
--- a/core/src/main/java/org/lflang/generator/c/CCompiler.java
+++ b/core/src/main/java/org/lflang/generator/c/CCompiler.java
@@ -42,6 +42,7 @@
 import org.lflang.target.property.CompilerProperty;
 import org.lflang.target.property.PlatformProperty;
 import org.lflang.target.property.PlatformProperty.PlatformOptions;
+import org.lflang.target.property.TracePluginProperty;
 import org.lflang.target.property.type.BuildTypeType.BuildType;
 import org.lflang.target.property.type.PlatformType.Platform;
 import org.lflang.util.FileUtil;
@@ -219,11 +220,13 @@ private static List<String> cmakeOptions(TargetConfig targetConfig, FileConfig f
     String maybeQuote = ""; // Windows seems to require extra level of quoting.
     String srcPath = fileConfig.srcPath.toString(); // Windows requires escaping the backslashes.
     String rootPath = fileConfig.srcPkgPath.toString();
+    String srcGenPath = fileConfig.getSrcGenPath().toString();
     if (separator.equals("\\")) {
       separator = "\\\\\\\\";
       maybeQuote = "\\\"";
       srcPath = srcPath.replaceAll("\\\\", "\\\\\\\\");
       rootPath = rootPath.replaceAll("\\\\", "\\\\\\\\");
+      srcGenPath = srcGenPath.replaceAll("\\\\", "\\\\\\\\");
     }
     arguments.addAll(
         List.of(
@@ -235,6 +238,14 @@ private static List<String> cmakeOptions(TargetConfig targetConfig, FileConfig f
             "-DCMAKE_INSTALL_BINDIR="
                 + FileUtil.toUnixString(fileConfig.getOutPath().relativize(fileConfig.binPath)),
             "-DLF_FILE_SEPARATOR=\"" + maybeQuote + separator + maybeQuote + "\""));
+    var tracePlugin = targetConfig.getOrDefault(TracePluginProperty.INSTANCE);
+    if (tracePlugin != null) {
+      arguments.add(
+          "-DLF_TRACE_PLUGIN="
+              + targetConfig
+                  .getOrDefault(TracePluginProperty.INSTANCE)
+                  .getImplementationArchiveFile());
+    }
     // Add #define for source file directory.
     // Do not do this for federated programs because for those, the definition is put
     // into the cmake file (and fileConfig.srcPath is the wrong directory anyway).
@@ -242,6 +253,7 @@ private static List<String> cmakeOptions(TargetConfig targetConfig, FileConfig f
       // Do not convert to Unix path
       arguments.add("-DLF_SOURCE_DIRECTORY=\"" + maybeQuote + srcPath + maybeQuote + "\"");
       arguments.add("-DLF_PACKAGE_DIRECTORY=\"" + maybeQuote + rootPath + maybeQuote + "\"");
+      arguments.add("-DLF_SOURCE_GEN_DIRECTORY=\"" + maybeQuote + srcGenPath + maybeQuote + "\"");
     }
     arguments.add(FileUtil.toUnixString(fileConfig.getSrcGenPath()));
 
diff --git a/core/src/main/java/org/lflang/generator/c/CConstructorGenerator.java b/core/src/main/java/org/lflang/generator/c/CConstructorGenerator.java
index 529e37a975..b18b8bc9a9 100644
--- a/core/src/main/java/org/lflang/generator/c/CConstructorGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CConstructorGenerator.java
@@ -16,7 +16,7 @@ public static String generateConstructor(TypeParameterizedReactor tpr, String co
     code.pr(structType + "* new_" + CUtil.getName(tpr) + "() {");
     code.indent();
     code.pr(
-        structType + "* self = (" + structType + "*)_lf_new_reactor(sizeof(" + structType + "));");
+        structType + "* self = (" + structType + "*)lf_new_reactor(sizeof(" + structType + "));");
     code.pr(constructorCode);
     code.pr("return self;");
     code.unindent();
diff --git a/core/src/main/java/org/lflang/generator/c/CEnvironmentFunctionGenerator.java b/core/src/main/java/org/lflang/generator/c/CEnvironmentFunctionGenerator.java
index b289a9978f..3789638ded 100644
--- a/core/src/main/java/org/lflang/generator/c/CEnvironmentFunctionGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CEnvironmentFunctionGenerator.java
@@ -78,7 +78,7 @@ private String generateEnvironmentEnum() {
   private String generateCreateEnvironments() {
     CodeBuilder code = new CodeBuilder();
     code.pr("// 'Create' and initialize the environments in the program");
-    code.pr("void _lf_create_environments() {");
+    code.pr("void lf_create_environments() {");
     code.indent();
     for (ReactorInstance enclave : enclaves) {
       // Decide the number of workers to use. If this is the top-level
diff --git a/core/src/main/java/org/lflang/generator/c/CGenerator.java b/core/src/main/java/org/lflang/generator/c/CGenerator.java
index afd2ce53da..86d45f4c48 100644
--- a/core/src/main/java/org/lflang/generator/c/CGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CGenerator.java
@@ -630,7 +630,7 @@ private void generateCodeFor(String lfModuleName) throws IOException {
       code.pr(
           """
                  #ifndef FEDERATED
-                 void terminate_execution(environment_t* env) {}
+                 void lf_terminate_execution(environment_t* env) {}
                  #endif""");
     }
   }
@@ -869,12 +869,14 @@ private void pickCompilePlatform() {
   /** Copy target-specific header file to the src-gen directory. */
   protected void copyTargetFiles() throws IOException {
     Path dest = fileConfig.getSrcGenPath();
+    var arduino = false;
     if (targetConfig.isSet(PlatformProperty.INSTANCE)) {
       var platform = targetConfig.get(PlatformProperty.INSTANCE).platform();
       switch (platform) {
         case ARDUINO -> {
           // For Arduino, alter the destination directory.
           dest = dest.resolve("src");
+          arduino = true;
         }
         case ZEPHYR -> {
           // For the Zephyr target, copy default config and board files.
@@ -903,8 +905,27 @@ protected void copyTargetFiles() throws IOException {
       Path coreLib = Paths.get(context.getArgs().externalRuntimeUri());
       FileUtil.copyDirectoryContents(coreLib, dest, true);
     } else {
-      FileUtil.copyFromClassPath("/lib/c/reactor-c/core", dest, true, false);
-      FileUtil.copyFromClassPath("/lib/c/reactor-c/lib", dest, true, false);
+      for (var directory : List.of("core", "lib")) {
+        FileUtil.copyFromClassPath("/lib/c/reactor-c/" + directory, dest, true, false);
+      }
+      for (var directory :
+          List.of("logging", "platform", "low_level_platform", "trace", "version", "tag")) {
+        var entry = "/lib/c/reactor-c/" + directory;
+        if (arduino) {
+          if (FileConfig.class.getResource(entry + "/api") != null) {
+            FileUtil.copyFromClassPath(
+                entry + "/api",
+                fileConfig.getSrcGenPath().resolve("include").resolve(directory),
+                true,
+                false);
+          }
+          if (FileConfig.class.getResource(entry + "/impl") != null) {
+            FileUtil.copyFromClassPath(entry + "/impl", dest.resolve(directory), true, false);
+          }
+        } else {
+          FileUtil.copyFromClassPath(entry, dest, true, false);
+        }
+      }
     }
   }
 
@@ -953,7 +974,11 @@ protected void generateReactorClassHeaders(
     }
     header.pr("#include \"include/core/reactor.h\"");
     src.pr("#include \"include/api/schedule.h\"");
-    src.pr("#include \"include/core/platform.h\"");
+    if (CPreambleGenerator.arduinoBased(targetConfig)) {
+      src.pr("#include \"include/low_level_platform/api/low_level_platform.h\"");
+    } else {
+      src.pr("#include \"low_level_platform/api/low_level_platform.h\"");
+    }
     generateIncludes(tpr);
     if (cppMode) {
       src.pr("}");
@@ -1360,13 +1385,10 @@ private void recordBuiltinTriggers(ReactorInstance instance) {
           if (targetConfig.get(TracingProperty.INSTANCE).isEnabled()) {
             var description = CUtil.getShortenedName(reactor);
             var reactorRef = CUtil.reactorRef(reactor);
-            var envTraceRef = CUtil.getEnvironmentStruct(reactor) + ".trace";
             temp.pr(
                 String.join(
                     "\n",
                     "_lf_register_trace_event("
-                        + envTraceRef
-                        + ","
                         + reactorRef
                         + ", &("
                         + reactorRef
diff --git a/core/src/main/java/org/lflang/generator/c/CMainFunctionGenerator.java b/core/src/main/java/org/lflang/generator/c/CMainFunctionGenerator.java
index a1d8cb652c..ba054d6e49 100644
--- a/core/src/main/java/org/lflang/generator/c/CMainFunctionGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CMainFunctionGenerator.java
@@ -101,11 +101,11 @@ private String generateSetDefaultCliOption() {
                 + StringUtil.addDoubleQuotes(
                     StringUtil.joinObjects(runCommand, StringUtil.addDoubleQuotes(", ")))
                 + " };",
-            "void _lf_set_default_command_line_options() {",
+            "void lf_set_default_command_line_options() {",
             "        default_argc = " + runCommand.size() + ";",
             "        default_argv = _lf_default_argv;",
             "}")
-        : "void _lf_set_default_command_line_options() {}";
+        : "void lf_set_default_command_line_options() {}";
   }
 
   /** Parse the target parameters and set flags to the runCommand accordingly. */
diff --git a/core/src/main/java/org/lflang/generator/c/CPortGenerator.java b/core/src/main/java/org/lflang/generator/c/CPortGenerator.java
index 44cf25dbd1..56c2d85ff7 100644
--- a/core/src/main/java/org/lflang/generator/c/CPortGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CPortGenerator.java
@@ -101,7 +101,7 @@ public static String initializeInputMultiport(PortInstance input, String reactor
               "\n",
               portRefName + "_width = " + input.getWidth() + ";",
               "// Allocate memory for multiport inputs.",
-              portRefName + " = (" + variableStructType(input) + "**)_lf_allocate(",
+              portRefName + " = (" + variableStructType(input) + "**)lf_allocate(",
               "        " + input.getWidth() + ", sizeof(" + variableStructType(input) + "*),",
               "        &" + reactorSelfStruct + "->base.allocations); ",
               "// Set inputs by default to an always absent default input.",
@@ -119,7 +119,7 @@ public static String initializeInputMultiport(PortInstance input, String reactor
             "\n",
             result,
             "if (" + input.getWidth() + " >= LF_SPARSE_WIDTH_THRESHOLD) {",
-            "    " + portRefName + "__sparse = (lf_sparse_io_record_t*)_lf_allocate(1,",
+            "    " + portRefName + "__sparse = (lf_sparse_io_record_t*)lf_allocate(1,",
             "            sizeof(lf_sparse_io_record_t) + sizeof(size_t) * "
                 + input.getWidth()
                 + "/LF_SPARSE_CAPACITY_DIVIDER,",
@@ -158,10 +158,10 @@ public static String initializeOutputMultiport(PortInstance output, String react
             "\n",
             portRefName + "_width = " + output.getWidth() + ";",
             "// Allocate memory for multiport output.",
-            portRefName + " = (" + portStructType + "*)_lf_allocate(",
+            portRefName + " = (" + portStructType + "*)lf_allocate(",
             "        " + output.getWidth() + ", sizeof(" + portStructType + "),",
             "        &" + reactorSelfStruct + "->base.allocations); ",
-            portRefName + "_pointers = (" + portStructType + "**)_lf_allocate(",
+            portRefName + "_pointers = (" + portStructType + "**)lf_allocate(",
             "        " + output.getWidth() + ", sizeof(" + portStructType + "*),",
             "        &" + reactorSelfStruct + "->base.allocations); ",
             "// Assign each output port pointer to be used in",
diff --git a/core/src/main/java/org/lflang/generator/c/CPreambleGenerator.java b/core/src/main/java/org/lflang/generator/c/CPreambleGenerator.java
index 080b4c5848..53b35002f4 100644
--- a/core/src/main/java/org/lflang/generator/c/CPreambleGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CPreambleGenerator.java
@@ -1,7 +1,5 @@
 package org.lflang.generator.c;
 
-import static org.lflang.util.StringUtil.addDoubleQuotes;
-
 import java.nio.file.Path;
 import java.util.HashMap;
 import org.lflang.generator.CodeBuilder;
@@ -32,7 +30,7 @@
  */
 public class CPreambleGenerator {
 
-  private static boolean arduinoBased(TargetConfig targetConfig) {
+  public static boolean arduinoBased(TargetConfig targetConfig) {
     return targetConfig.isSet(PlatformProperty.INSTANCE)
         && targetConfig.get(PlatformProperty.INSTANCE).platform() == Platform.ARDUINO;
   }
@@ -43,7 +41,11 @@ public static String generateIncludeStatements(TargetConfig targetConfig, boolea
       code.pr("extern \"C\" {");
     }
     code.pr("#include <limits.h>");
-    code.pr("#include \"include/core/platform.h\"");
+    if (arduinoBased(targetConfig)) {
+      code.pr("#include \"include/low_level_platform/api/low_level_platform.h\"");
+    } else {
+      code.pr("#include \"low_level_platform/api/low_level_platform.h\"");
+    }
     CCoreFilesUtils.getCTargetHeader()
         .forEach(it -> code.pr("#include " + StringUtil.addDoubleQuotes(it)));
     code.pr("#include \"include/core/reactor.h\"");
@@ -53,7 +55,7 @@ public static String generateIncludeStatements(TargetConfig targetConfig, boolea
     }
 
     if (targetConfig.get(TracingProperty.INSTANCE).isEnabled()) {
-      code.pr("#include \"include/core/trace.h\"");
+      code.pr("#include \"trace/api/trace.h\"");
     }
     code.pr("#include \"include/core/mixed_radix.h\"");
     code.pr("#include \"include/core/port.h\"");
@@ -76,7 +78,6 @@ public static String generateDefineDirectives(TargetConfig targetConfig, Path sr
     CodeBuilder code = new CodeBuilder();
     // TODO: Get rid of all of these
     code.pr("#define LOG_LEVEL " + logLevel);
-    code.pr("#define TARGET_FILES_DIRECTORY " + addDoubleQuotes(srcGenPath.toString()));
     final var definitions = new HashMap<String, String>();
     if (tracing.isEnabled()) {
       definitions.put("LF_TRACE", tracing.traceFileName);
diff --git a/core/src/main/java/org/lflang/generator/c/CTracingGenerator.java b/core/src/main/java/org/lflang/generator/c/CTracingGenerator.java
index b013913756..8439d562b0 100644
--- a/core/src/main/java/org/lflang/generator/c/CTracingGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CTracingGenerator.java
@@ -30,12 +30,10 @@ public static String generateTraceTableEntries(ReactorInstance instance) {
     List<String> code = new ArrayList<>();
     var description = CUtil.getShortenedName(instance);
     var selfStruct = CUtil.reactorRef(instance);
-    var envTraceRef = CUtil.getEnvironmentStruct(instance) + ".trace";
-    code.add(registerTraceEvent(envTraceRef, selfStruct, "NULL", "trace_reactor", description));
+    code.add(registerTraceEvent(selfStruct, "NULL", "trace_reactor", description));
     for (ActionInstance action : instance.actions) {
       code.add(
           registerTraceEvent(
-              envTraceRef,
               selfStruct,
               getTrigger(selfStruct, action.getName()),
               "trace_trigger",
@@ -44,7 +42,6 @@ public static String generateTraceTableEntries(ReactorInstance instance) {
     for (TimerInstance timer : instance.timers) {
       code.add(
           registerTraceEvent(
-              envTraceRef,
               selfStruct,
               getTrigger(selfStruct, timer.getName()),
               "trace_trigger",
@@ -54,10 +51,8 @@ public static String generateTraceTableEntries(ReactorInstance instance) {
   }
 
   private static String registerTraceEvent(
-      String envTrace, String obj, String trigger, String type, String description) {
+      String obj, String trigger, String type, String description) {
     return "_lf_register_trace_event("
-        + envTrace
-        + ", "
         + obj
         + ", "
         + trigger
diff --git a/core/src/main/java/org/lflang/generator/c/CTriggerObjectsGenerator.java b/core/src/main/java/org/lflang/generator/c/CTriggerObjectsGenerator.java
index bd4f844912..ae2d91bc40 100644
--- a/core/src/main/java/org/lflang/generator/c/CTriggerObjectsGenerator.java
+++ b/core/src/main/java/org/lflang/generator/c/CTriggerObjectsGenerator.java
@@ -230,10 +230,12 @@ private static boolean setReactionPriorities(ReactorInstance reactor, CodeBuilde
 
       if (levelSet.size() == 1 && deadlineSet.size() == 1) {
         // Scenario (1)
-
-        var indexValue = inferredDeadline.toNanoSeconds() << 16 | level;
-
-        var reactionIndex = "0x" + Long.toUnsignedString(indexValue, 16) + "LL";
+        var reactionIndex =
+            "lf_combine_deadline_and_level("
+                + inferredDeadline.toNanoSeconds()
+                + ", "
+                + level
+                + ")";
 
         temp.pr(
             String.join(
@@ -251,13 +253,13 @@ private static boolean setReactionPriorities(ReactorInstance reactor, CodeBuilde
                 "// index is the OR of levels[" + runtimeIdx + "] and ",
                 "// deadlines[" + runtimeIdx + "] shifted left 16 bits.",
                 CUtil.reactionRef(r)
-                    + ".index = ("
+                    + ".index = lf_combine_deadline_and_level("
                     + r.uniqueID()
                     + "_inferred_deadlines["
                     + runtimeIdx
-                    + "] << 16) | "
+                    + "], "
                     + level
-                    + ";"));
+                    + ");"));
 
       } else if (levelSet.size() > 1 && deadlineSet.size() == 1) {
         // Scenarion (3)
@@ -268,13 +270,13 @@ private static boolean setReactionPriorities(ReactorInstance reactor, CodeBuilde
                 "// index is the OR of levels[" + runtimeIdx + "] and ",
                 "// deadlines[" + runtimeIdx + "] shifted left 16 bits.",
                 CUtil.reactionRef(r)
-                    + ".index = ("
+                    + ".index = lf_combine_deadline_and_level("
                     + inferredDeadline.toNanoSeconds()
-                    + " << 16) | "
+                    + ", "
                     + r.uniqueID()
                     + "_levels["
                     + runtimeIdx
-                    + "];"));
+                    + "]);"));
 
       } else if (levelSet.size() > 1 && deadlineSet.size() > 1) {
         // Scenario (4)
@@ -285,15 +287,15 @@ private static boolean setReactionPriorities(ReactorInstance reactor, CodeBuilde
                 "// index is the OR of levels[" + runtimeIdx + "] and ",
                 "// deadlines[" + runtimeIdx + "] shifted left 16 bits.",
                 CUtil.reactionRef(r)
-                    + ".index = ("
+                    + ".index = inferredDeadline.toNanoSeconds("
                     + r.uniqueID()
                     + "_inferred_deadlines["
                     + runtimeIdx
-                    + "] << 16) | "
+                    + "], "
                     + r.uniqueID()
                     + "_levels["
                     + runtimeIdx
-                    + "];"));
+                    + "]);"));
       }
     }
     for (ReactorInstance child : reactor.children) {
@@ -569,7 +571,7 @@ private static String deferredFillTriggerTable(Iterable<ReactionInstance> reacti
                   "// For reaction " + reaction.index + " of " + name + ", allocate an",
                   "// array of trigger pointers for downstream reactions through port "
                       + port.getFullName(),
-                  "trigger_t** trigger_array = (trigger_t**)_lf_allocate(",
+                  "trigger_t** trigger_array = (trigger_t**)lf_allocate(",
                   "        " + srcRange.destinations.size() + ", sizeof(trigger_t*),",
                   "        &" + reactorSelfStruct + "->base.allocations); ",
                   triggerArray + " = trigger_array;"));
@@ -967,13 +969,13 @@ private static String deferredReactionOutputs(
               "\n",
               "// Allocate memory for triggers[] and triggered_sizes[] on the reaction_t",
               "// struct for this reaction.",
-              CUtil.reactionRef(reaction) + ".triggers = (trigger_t***)_lf_allocate(",
+              CUtil.reactionRef(reaction) + ".triggers = (trigger_t***)lf_allocate(",
               "        " + outputCount + ", sizeof(trigger_t**),",
               "        &" + reactorSelfStruct + "->base.allocations);",
-              CUtil.reactionRef(reaction) + ".triggered_sizes = (int*)_lf_allocate(",
+              CUtil.reactionRef(reaction) + ".triggered_sizes = (int*)lf_allocate(",
               "        " + outputCount + ", sizeof(int),",
               "        &" + reactorSelfStruct + "->base.allocations);",
-              CUtil.reactionRef(reaction) + ".output_produced = (bool**)_lf_allocate(",
+              CUtil.reactionRef(reaction) + ".output_produced = (bool**)lf_allocate(",
               "        " + outputCount + ", sizeof(bool*),",
               "        &" + reactorSelfStruct + "->base.allocations);"));
     }
@@ -1029,7 +1031,7 @@ private static String deferredReactionMemory(
                       + width
                       + ";",
                   CUtil.reactorRefNested(trigger.getParent()) + "." + trigger.getName(),
-                  "        = (" + portStructType + "**)_lf_allocate(",
+                  "        = (" + portStructType + "**)lf_allocate(",
                   "                " + width + ", sizeof(" + portStructType + "*),",
                   "                &" + reactorSelfStruct + "->base.allocations); "));
 
@@ -1071,11 +1073,11 @@ private static String deferredAllocationForEffectsOnInputs(ReactorInstance react
                   effectRef + "_width = " + effect.getWidth() + ";",
                   "// Allocate memory to store output of reaction feeding ",
                   "// a multiport input of a contained reactor.",
-                  effectRef + " = (" + portStructType + "**)_lf_allocate(",
+                  effectRef + " = (" + portStructType + "**)lf_allocate(",
                   "        " + effect.getWidth() + ", sizeof(" + portStructType + "*),",
                   "        &" + reactorSelfStruct + "->base.allocations); ",
                   "for (int i = 0; i < " + effect.getWidth() + "; i++) {",
-                  "    " + effectRef + "[i] = (" + portStructType + "*)_lf_allocate(",
+                  "    " + effectRef + "[i] = (" + portStructType + "*)lf_allocate(",
                   "            1, sizeof(" + portStructType + "),",
                   "            &" + reactorSelfStruct + "->base.allocations); ",
                   "}"));
diff --git a/core/src/main/java/org/lflang/generator/docker/CDockerGenerator.java b/core/src/main/java/org/lflang/generator/docker/CDockerGenerator.java
index d3e4c64eeb..62c61ed216 100644
--- a/core/src/main/java/org/lflang/generator/docker/CDockerGenerator.java
+++ b/core/src/main/java/org/lflang/generator/docker/CDockerGenerator.java
@@ -40,7 +40,7 @@ protected String generateDockerFileContent() {
         "# For instructions, see: https://www.lf-lang.org/docs/handbook/containerized-execution",
         "FROM " + baseImage + " AS builder",
         "WORKDIR /lingua-franca/" + lfModuleName,
-        "RUN set -ex && apk add --no-cache " + compiler + " musl-dev cmake make",
+        generateRunForBuildDependencies(),
         "COPY . src-gen",
         compileCommand,
         "",
diff --git a/core/src/main/java/org/lflang/target/Target.java b/core/src/main/java/org/lflang/target/Target.java
index a01b863303..573b121566 100644
--- a/core/src/main/java/org/lflang/target/Target.java
+++ b/core/src/main/java/org/lflang/target/Target.java
@@ -57,6 +57,7 @@
 import org.lflang.target.property.SchedulerProperty;
 import org.lflang.target.property.SingleFileProjectProperty;
 import org.lflang.target.property.SingleThreadedProperty;
+import org.lflang.target.property.TracePluginProperty;
 import org.lflang.target.property.TracingProperty;
 import org.lflang.target.property.VerifyProperty;
 import org.lflang.target.property.WorkersProperty;
@@ -605,6 +606,7 @@ public void initialize(TargetConfig config) {
           SchedulerProperty.INSTANCE,
           SingleThreadedProperty.INSTANCE,
           TracingProperty.INSTANCE,
+          TracePluginProperty.INSTANCE,
           VerifyProperty.INSTANCE,
           WorkersProperty.INSTANCE);
       case CPP -> config.register(
diff --git a/core/src/main/java/org/lflang/target/TargetConfig.java b/core/src/main/java/org/lflang/target/TargetConfig.java
index 6170947db0..f3dc1695f6 100644
--- a/core/src/main/java/org/lflang/target/TargetConfig.java
+++ b/core/src/main/java/org/lflang/target/TargetConfig.java
@@ -63,6 +63,10 @@
  */
 public class TargetConfig {
 
+  /** Error message to use when a target property does not exist in LF syntax. */
+  public static final String NOT_IN_LF_SYNTAX_MESSAGE =
+      "There is no representation of this property in the LF target property syntax";
+
   /** The target of this configuration (e.g., C, TypeScript, Python). */
   public final Target target;
 
@@ -173,10 +177,9 @@ protected void load(JsonObject jsonObject, MessageReporter messageReporter) {
    * @param stage2 The second stage an the error reporter through which to report the warning.
    */
   public void reportUnsupportedTargetProperty(String name, MessageReporter.Stage2 stage2) {
-    stage2.warning(
+    stage2.error(
         String.format(
-            "The target property '%s' is not supported by the %s target and is thus ignored.",
-            name, this.target));
+            "The target property '%s' is not supported by the %s target.", name, this.target));
     stage2.info("Recognized properties are: " + this.listOfRegisteredProperties());
   }
 
diff --git a/core/src/main/java/org/lflang/target/property/TargetProperty.java b/core/src/main/java/org/lflang/target/property/TargetProperty.java
index d2d630d6b3..e1e1c444df 100644
--- a/core/src/main/java/org/lflang/target/property/TargetProperty.java
+++ b/core/src/main/java/org/lflang/target/property/TargetProperty.java
@@ -126,7 +126,9 @@ public void update(TargetConfig config, T value) {
   }
 
   /**
-   * Update the given configuration based on the given corresponding AST node.
+   * Update the given configuration based on the given corresponding AST node. If the given
+   * configuration does not belong in the AST, then report an error using the error message given by
+   * {@code TargetConfig.NOT_IN_LF_SYNTAX_MESSAGE}.
    *
    * @param config The configuration to update.
    * @param pair The pair that holds the value to perform the update with.
diff --git a/core/src/main/java/org/lflang/target/property/TracePluginProperty.java b/core/src/main/java/org/lflang/target/property/TracePluginProperty.java
new file mode 100644
index 0000000000..2d150b9fab
--- /dev/null
+++ b/core/src/main/java/org/lflang/target/property/TracePluginProperty.java
@@ -0,0 +1,56 @@
+package org.lflang.target.property;
+
+import org.lflang.MessageReporter;
+import org.lflang.lf.Element;
+import org.lflang.target.TargetConfig;
+import org.lflang.target.property.TracePluginProperty.TracePluginOptions;
+import org.lflang.target.property.type.PrimitiveType;
+
+/** Property that provides an alternative tracing implementation. */
+public class TracePluginProperty extends TargetProperty<TracePluginOptions, PrimitiveType> {
+
+  /** Singleton target property instance. */
+  public static final TracePluginProperty INSTANCE = new TracePluginProperty();
+
+  private TracePluginProperty() {
+    super(PrimitiveType.STRING);
+  }
+
+  @Override
+  public TracePluginOptions initialValue() {
+    return null;
+  }
+
+  @Override
+  protected TracePluginOptions fromAst(Element node, MessageReporter reporter) {
+    reporter.at(node).error(TargetConfig.NOT_IN_LF_SYNTAX_MESSAGE);
+    return null;
+  }
+
+  @Override
+  protected TracePluginOptions fromString(String s, MessageReporter reporter) {
+    return new TracePluginOptions(s);
+  }
+
+  @Override
+  public String name() {
+    return "trace-plugin";
+  }
+
+  @Override
+  public Element toAstElement(TracePluginOptions value) {
+    throw new UnsupportedOperationException(TargetConfig.NOT_IN_LF_SYNTAX_MESSAGE);
+  }
+
+  public static class TracePluginOptions {
+    private final String implementationArchiveFile;
+
+    public TracePluginOptions(String implementationArchiveFile) {
+      this.implementationArchiveFile = implementationArchiveFile;
+    }
+
+    public String getImplementationArchiveFile() {
+      return implementationArchiveFile;
+    }
+  }
+}
diff --git a/core/src/main/java/org/lflang/util/FileUtil.java b/core/src/main/java/org/lflang/util/FileUtil.java
index ade0def1c2..67b62d9a59 100644
--- a/core/src/main/java/org/lflang/util/FileUtil.java
+++ b/core/src/main/java/org/lflang/util/FileUtil.java
@@ -663,6 +663,7 @@ public static void arduinoDeleteHelper(Path srcGenPath, boolean threadingOn) thr
       deleteDirectory(srcGenPath.resolve("include/core/threaded"));
       deleteDirectory(srcGenPath.resolve("src/core/platform/arduino_mbed"));
     }
+    deleteDirectory(srcGenPath.resolve("src").resolve("trace"));
     // Delete all the federated headers
     deleteDirectory(srcGenPath.resolve("include/core/federated"));
     // arduino-cli needs all headers to be under a "include" directory.
@@ -748,7 +749,9 @@ public static void relativeIncludeHelper(
       if (path.getFileName().toString().contains("CMakeLists.txt")) continue;
       if (fileStringToFilePath.put(fileName, path) != null) {
         throw new IOException(
-            "Directory has different files with the same name. Cannot Relativize.");
+            String.format(
+                "Directory has different files with the same name (%s). Cannot relativize.",
+                fileName));
       }
     }
     Pattern regexExpression = Pattern.compile("#include\s+[\"]([^\"]+)*[\"]");
diff --git a/core/src/main/kotlin/org/lflang/generator/cpp/CppAssembleMethodGenerator.kt b/core/src/main/kotlin/org/lflang/generator/cpp/CppAssembleMethodGenerator.kt
index 1a12f6424a..b09ebffb6b 100644
--- a/core/src/main/kotlin/org/lflang/generator/cpp/CppAssembleMethodGenerator.kt
+++ b/core/src/main/kotlin/org/lflang/generator/cpp/CppAssembleMethodGenerator.kt
@@ -30,6 +30,7 @@ import org.lflang.generator.cpp.CppInstanceGenerator.Companion.isEnclave
 import org.lflang.generator.cpp.CppPortGenerator.Companion.dataType
 import org.lflang.lf.Action
 import org.lflang.lf.Connection
+import org.lflang.lf.Instantiation
 import org.lflang.lf.ParameterReference
 import org.lflang.lf.Port
 import org.lflang.lf.Reaction
@@ -51,22 +52,23 @@ class CppAssembleMethodGenerator(private val reactor: Reactor) {
         generateCode: (String) -> String
     ): String {
         val port = varRef.variable as Port
-        val container = varRef.container
+        val container: Instantiation? = varRef.container
+        val instanceRef = if (container?.isEnclave == true) "__lf_instance->" else ""
         return with(PrependOperator) {
             if (port.isMultiport) {
                 if (container?.isBank == true) {
                     if (varRef.isInterleaved) {
                         """
-                            |for (size_t __lf_port_idx = 0; __lf_port_idx < ${container.name}[0]->${port.name}.size(); __lf_port_idx++) {
+                            |for (size_t __lf_port_idx = 0; __lf_port_idx < ${container.name}[0]->$instanceRef${port.name}.size(); __lf_port_idx++) {
                             |  for (auto& __lf_instance : ${container.name}) {
-                        ${" |    "..generateCode("__lf_instance->${port.name}[__lf_port_idx]")}
+                        ${" |    "..generateCode("__lf_instance->$instanceRef${port.name}[__lf_port_idx]")}
                             |  }
                             |}
                         """.trimMargin()
                     } else {
                         """
                             |for (auto& __lf_instance : ${container.name}) {
-                            |  for (auto& __lf_port : __lf_instance->${port.name}) {
+                            |  for (auto& __lf_port : __lf_instance->$instanceRef${port.name}) {
                         ${" |    "..generateCode("__lf_port")}
                             |  }
                             |}
@@ -85,7 +87,7 @@ class CppAssembleMethodGenerator(private val reactor: Reactor) {
                     // is in a bank, but not a multiport
                     """
                         |for (auto& __lf_instance : ${container.name}) {
-                    ${" |  "..generateCode("__lf_instance->${if(container.isEnclave) "__lf_instance->" else ""}${port.name}")}
+                    ${" |  "..generateCode("__lf_instance->$instanceRef${port.name}")}
                         |}
                     """.trimMargin()
                 } else {
@@ -197,7 +199,7 @@ class CppAssembleMethodGenerator(private val reactor: Reactor) {
 
     private fun Connection.getConnectionLambda(portType: String): String {
         return """
-            [this]($portType left, $portType right) {
+            [&]($portType left, $portType right) {
                 left->environment()->draw_connection(left, right, $properties);
             }
         """.trimIndent()
diff --git a/core/src/main/kotlin/org/lflang/generator/cpp/CppParameterGenerator.kt b/core/src/main/kotlin/org/lflang/generator/cpp/CppParameterGenerator.kt
index 3c2224e031..3cd064b1ad 100644
--- a/core/src/main/kotlin/org/lflang/generator/cpp/CppParameterGenerator.kt
+++ b/core/src/main/kotlin/org/lflang/generator/cpp/CppParameterGenerator.kt
@@ -67,5 +67,7 @@ class CppParameterGenerator(private val reactor: Reactor) {
      *  This is required for some code bodies (e.g. target code in parameter initializers) to have access to the local parameters.
      */
     fun generateOuterAliasDeclarations() =
-        reactor.parameters.joinToString(separator = "") { "const typename Parameters::${it.typeAlias}& ${it.name} = __lf_inner.${it.name};\n" }
+        reactor.parameters.joinToString(prefix = "// parameter aliases for use in the outer scope\n", separator = "") {
+            "[[maybe_unused]] const typename Parameters::${it.typeAlias}& ${it.name} = __lf_inner.${it.name};\n"
+        }
 }
diff --git a/core/src/main/kotlin/org/lflang/generator/cpp/CppReactorGenerator.kt b/core/src/main/kotlin/org/lflang/generator/cpp/CppReactorGenerator.kt
index e6cf197e06..97bf0541e4 100644
--- a/core/src/main/kotlin/org/lflang/generator/cpp/CppReactorGenerator.kt
+++ b/core/src/main/kotlin/org/lflang/generator/cpp/CppReactorGenerator.kt
@@ -94,8 +94,8 @@ class CppReactorGenerator(private val reactor: Reactor, fileConfig: CppFileConfi
         ${" |  "..reactions.generateReactionViewForwardDeclarations()}
             |
             |  class Inner: public lfutil::LFScope {
-            |    const Inner& __lf_inner = *this;
-            |    const Parameters __lf_parameters;
+            |    [[maybe_unused]] const Inner& __lf_inner = *this;
+            |    [[maybe_unused]] const Parameters __lf_parameters;
         ${" |    "..parameters.generateInnerAliasDeclarations()}
         ${" |    "..state.generateDeclarations()}
         ${" |    "..methods.generateDeclarations()}
diff --git a/core/src/main/resources/lib/c/reactor-c b/core/src/main/resources/lib/c/reactor-c
index 18fd6ee621..277d3f2951 160000
--- a/core/src/main/resources/lib/c/reactor-c
+++ b/core/src/main/resources/lib/c/reactor-c
@@ -1 +1 @@
-Subproject commit 18fd6ee6212ba127aea5d7918e26a6e28d4068e7
+Subproject commit 277d3f295167b9f9f3b45356937af8cf57bef3b8
diff --git a/core/src/main/resources/lib/platform/zephyr/prj_lf.conf b/core/src/main/resources/lib/platform/zephyr/prj_lf.conf
index 88613edc08..6b171daff2 100644
--- a/core/src/main/resources/lib/platform/zephyr/prj_lf.conf
+++ b/core/src/main/resources/lib/platform/zephyr/prj_lf.conf
@@ -12,3 +12,4 @@ CONFIG_NEWLIB_LIBC=y
 CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y
 # Enable the counter API used for hi-res clock
 CONFIG_COUNTER=y
+CONFIG_THREAD_CUSTOM_DATA=y
diff --git a/core/src/test/java/org/lflang/tests/compiler/LinguaFrancaValidationTest.java b/core/src/test/java/org/lflang/tests/compiler/LinguaFrancaValidationTest.java
index 11fff6c2c9..577c02eb23 100644
--- a/core/src/test/java/org/lflang/tests/compiler/LinguaFrancaValidationTest.java
+++ b/core/src/test/java/org/lflang/tests/compiler/LinguaFrancaValidationTest.java
@@ -34,6 +34,7 @@
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import org.eclipse.xtext.diagnostics.Severity;
 import org.eclipse.xtext.testing.InjectWith;
 import org.eclipse.xtext.testing.extensions.InjectionExtension;
 import org.eclipse.xtext.testing.util.ParseHelper;
@@ -1580,7 +1581,17 @@ public Collection<DynamicTest> checkTargetProperties() throws Exception {
                   Model model = createModel(Target.C, property, it);
                   System.out.println(property.name());
                   System.out.println(it.toString());
-                  validator.assertNoErrors(model);
+                  var issues = validator.validate(model);
+                  if (!issues.stream()
+                      .allMatch(
+                          issue ->
+                              issue.getSeverity() != Severity.ERROR
+                                  || issue
+                                      .getMessage()
+                                      .equals(TargetConfig.NOT_IN_LF_SYNTAX_MESSAGE))) {
+                    throw new RuntimeException(
+                        "there were unexpected errors in the generated model");
+                  }
                   // Also make sure warnings are produced when files are not present.
                   if (type == PrimitiveType.FILE) {
                     validator.assertWarning(
@@ -1905,11 +1916,11 @@ public void testInvalidTargetParam() throws Exception {
     var model = parseWithoutError(testCase);
     List<Issue> issues = validator.validate(model);
     Assertions.assertTrue(issues.size() == 2);
-    validator.assertWarning(
+    validator.assertError(
         model,
         LfPackage.eINSTANCE.getKeyValuePair(),
         null,
-        "The target property 'foobarbaz' is not supported by the C target and is thus ignored.");
+        "The target property 'foobarbaz' is not supported by the C target.");
   }
 
   @Test
@@ -1922,12 +1933,11 @@ public void testTargetParamNotSupportedForTarget() throws Exception {
     var model = parseWithoutError(testCase);
     List<Issue> issues = validator.validate(model);
     Assertions.assertTrue(issues.size() == 2);
-    validator.assertWarning(
+    validator.assertError(
         model,
         LfPackage.eINSTANCE.getKeyValuePair(),
         null,
-        "The target property 'cargo-features' is not supported by the Python target and is thus"
-            + " ignored.");
+        "The target property 'cargo-features' is not supported by the Python target.");
   }
 
   @Test
diff --git a/test/C/src/concurrent/Threaded.lf b/test/C/src/concurrent/Threaded.lf
index 88a9acd6b6..a9598ca610 100644
--- a/test/C/src/concurrent/Threaded.lf
+++ b/test/C/src/concurrent/Threaded.lf
@@ -6,8 +6,7 @@
 // that without threads, this takes more than 800 msec to complete 200 msec of logical time. See
 // ThreadedMultiport for a parameterized version of this.
 target C {
-  timeout: 2 sec,
-  flags: ""  // Disable compiler optimization so that TakeTime actually takes time.
+  timeout: 2 sec
 }
 
 reactor Source {
diff --git a/test/C/src/concurrent/ThreadedMultiport.lf b/test/C/src/concurrent/ThreadedMultiport.lf
index 6fce42f0e9..cc09d36868 100644
--- a/test/C/src/concurrent/ThreadedMultiport.lf
+++ b/test/C/src/concurrent/ThreadedMultiport.lf
@@ -1,7 +1,6 @@
 // Check multiport capabilities on Outputs.
 target C {
-  timeout: 2 sec,
-  flags: ""  // Disable compiler optimization so that TakeTime actually takes time.
+  timeout: 2 sec
 }
 
 reactor Source(width: int = 4) {
diff --git a/test/C/src/concurrent/ThreadedThreaded.lf b/test/C/src/concurrent/ThreadedThreaded.lf
index 0b011b3118..6ad5204e02 100644
--- a/test/C/src/concurrent/ThreadedThreaded.lf
+++ b/test/C/src/concurrent/ThreadedThreaded.lf
@@ -6,8 +6,7 @@
 // of this.
 target C {
   timeout: 2 sec,
-  tracing: true,
-  flags: ""  // Disable compiler optimization so that TakeTime actually takes time.
+  tracing: true
 }
 
 reactor Source {
diff --git a/test/C/src/concurrent/Tracing.lf b/test/C/src/concurrent/Tracing.lf
index 983c9e737a..e0b0deb41b 100644
--- a/test/C/src/concurrent/Tracing.lf
+++ b/test/C/src/concurrent/Tracing.lf
@@ -2,7 +2,6 @@
 target C {
   timeout: 2 sec,
   tracing: true,
-  flags: "",  // Disable compiler optimization so that TakeTime actually takes time.
   logging: DEBUG
 }
 
diff --git a/test/C/src/federated/LoopDistributedCentralizedPhysicalAction.lf b/test/C/src/federated/LoopDistributedCentralizedPhysicalAction.lf
index ac783f07cc..59931b7f2c 100644
--- a/test/C/src/federated/LoopDistributedCentralizedPhysicalAction.lf
+++ b/test/C/src/federated/LoopDistributedCentralizedPhysicalAction.lf
@@ -4,7 +4,6 @@
  * @author Edward A. Lee
  */
 target C {
-  flags: "-Wall",
   coordination: centralized,
   coordination-options: {
     advance-message-interval: 100 msec
diff --git a/test/C/src/federated/LoopDistributedCentralizedPrecedence.lf b/test/C/src/federated/LoopDistributedCentralizedPrecedence.lf
index 51a10faac2..6b495a29d9 100644
--- a/test/C/src/federated/LoopDistributedCentralizedPrecedence.lf
+++ b/test/C/src/federated/LoopDistributedCentralizedPrecedence.lf
@@ -6,7 +6,6 @@
  * @author Soroush Bateni
  */
 target C {
-  flags: "-Wall",
   coordination: centralized,
   coordination-options: {
     advance-message-interval: 100 msec
diff --git a/test/C/src/federated/LoopDistributedCentralizedPrecedenceHierarchy.lf b/test/C/src/federated/LoopDistributedCentralizedPrecedenceHierarchy.lf
index 82adfca699..9d33a7ec1f 100644
--- a/test/C/src/federated/LoopDistributedCentralizedPrecedenceHierarchy.lf
+++ b/test/C/src/federated/LoopDistributedCentralizedPrecedenceHierarchy.lf
@@ -6,7 +6,6 @@
  * @author Soroush Bateni
  */
 target C {
-  flags: "-Wall",
   coordination: centralized,
   coordination-options: {
     advance-message-interval: 100 msec
diff --git a/test/Cpp/src/enclave/EnclaveCommunicationMultiportBankToMultiportBank.lf b/test/Cpp/src/enclave/EnclaveCommunicationMultiportBankToMultiportBank.lf
new file mode 100644
index 0000000000..92c03efdee
--- /dev/null
+++ b/test/Cpp/src/enclave/EnclaveCommunicationMultiportBankToMultiportBank.lf
@@ -0,0 +1,67 @@
+target Cpp {
+  timeout: 1 s,
+  workers: 1
+}
+
+reactor Src(bank_index: std::size_t = 0) {
+  timer t(0, 100 ms)
+  output[4] out: int
+  state counter: int = 0
+
+  reaction(t) -> out {=
+    for (auto& port : out) {
+      port.set(bank_index + counter);
+    }
+    counter = counter + 4;
+  =}
+}
+
+reactor Sink(bank_index: std::size_t = 0) {
+  timer t(0, 50 ms)
+  input[4] in: int
+  state received: bool = false
+  state iteration: int = 0
+
+  reaction(in) {=
+    received = true;
+    int value[4] = {0,0,0,0};
+    for(int i=0; i<4; i++){
+      value[i] = *in[i].get();
+      reactor::log::Info() << "Sink"<< bank_index << ": Received " << value[i] << " in port:" << i << " at " << get_elapsed_logical_time();
+    }
+
+    for(int i=0; i<4; i++){
+      if (value[i] != iteration*4 + bank_index) {
+          reactor::log::Error() << "Expected to recive " << iteration*4 + bank_index;
+          exit(1);
+      }
+    }
+
+    auto expected = 100ms * iteration;
+    iteration++;
+    if (get_elapsed_logical_time() != expected) {
+      reactor::log::Error() << "Expected value at " << expected;
+      exit(1);
+    }
+  =}
+
+  reaction(shutdown) {=
+    if(!received) {
+      reactor::log::Error() << "Nothing received.";
+      exit(1);
+    }
+  =}
+
+  reaction(t) {=
+    reactor::log::Info() << "Tick";
+  =}
+}
+
+main reactor {
+  @enclave(each = true)
+  src = new[4] Src()
+  @enclave(each = true)
+  sink = new[4] Sink()
+
+  src.out -> sink.in
+}
diff --git a/test/Cpp/src/enclave/EnclaveCommunicationMultiportBankToMultiportBankInterleave.lf b/test/Cpp/src/enclave/EnclaveCommunicationMultiportBankToMultiportBankInterleave.lf
new file mode 100644
index 0000000000..aabce4bbd9
--- /dev/null
+++ b/test/Cpp/src/enclave/EnclaveCommunicationMultiportBankToMultiportBankInterleave.lf
@@ -0,0 +1,67 @@
+target Cpp {
+  timeout: 1 s,
+  workers: 1
+}
+
+reactor Src(bank_index: std::size_t = 0) {
+  timer t(0, 100 ms)
+  output[4] out: int
+  state counter: int = 0
+
+  reaction(t) -> out {=
+    for (auto& port : out) {
+      port.set(bank_index + counter);
+    }
+    counter = counter + 4;
+  =}
+}
+
+reactor Sink(bank_index: std::size_t = 0) {
+  timer t(0, 50 ms)
+  input[4] in: int
+  state received: bool = false
+  state iteration: int = 0
+
+  reaction(in) {=
+    received = true;
+    int value[4] = {0,0,0,0};
+    for(int i=0; i<4; i++){
+      value[i] = *in[i].get();
+      reactor::log::Info() << "Sink"<< bank_index << ": Received " << value[i] << " in port:" << i << " at " << get_elapsed_logical_time();
+    }
+
+    for(int i=0; i<4; i++){
+      if (value[i] != iteration*4 + i) {
+          reactor::log::Error() << "Expected to recive " << iteration*4 + i;
+          exit(1);
+      }
+    }
+
+    auto expected = 100ms * iteration;
+    iteration++;
+    if (get_elapsed_logical_time() != expected) {
+      reactor::log::Error() << "Expected value at " << expected;
+      exit(1);
+    }
+  =}
+
+  reaction(shutdown) {=
+    if(!received) {
+      reactor::log::Error() << "Nothing received.";
+      exit(1);
+    }
+  =}
+
+  reaction(t) {=
+    reactor::log::Info() << "Tick";
+  =}
+}
+
+main reactor {
+  @enclave(each = true)
+  src = new[4] Src()
+  @enclave(each = true)
+  sink = new[4] Sink()
+
+  src.out -> interleaved(sink.in)
+}
diff --git a/test/Cpp/src/multiport/MultiportToMultiportAfterParameterized.lf b/test/Cpp/src/multiport/MultiportToMultiportAfterParameterized.lf
new file mode 100644
index 0000000000..d0b1b6ae6e
--- /dev/null
+++ b/test/Cpp/src/multiport/MultiportToMultiportAfterParameterized.lf
@@ -0,0 +1,42 @@
+// Test multiport to multiport connections. See also MultiportToMultiport.
+target Cpp
+
+reactor Source(width: size_t = 2) {
+  output[width] out: size_t
+
+  reaction(startup) -> out {=
+    for (size_t i = 0; i < out.size(); i++) {
+      out[i].set(i);
+    }
+  =}
+}
+
+reactor Destination(width: size_t = 2) {
+  input[width] in: size_t
+
+  reaction(in) {=
+    for (size_t i = 0; i < in.size(); i++) {
+      if (in[i].is_present()) {
+        size_t value = *in[i].get();
+        std::cout << "Received on channel " << i << ": " << value << '\n';
+        // NOTE: For testing purposes, this assumes the specific
+        // widths instantiated below.
+        if (value != i % 3) {
+          std::cerr << "ERROR: expected " << i % 3 << '\n';
+          exit(1);
+        }
+      }
+    }
+    if (get_elapsed_logical_time() != 1s) {
+      std::cerr << "ERROR: Expected to receive input after one second.\n";
+      exit(2);
+    }
+  =}
+}
+
+main reactor(delay: time = 1 sec) {
+  a1 = new Source(width=3)
+  a2 = new Source(width=2)
+  b = new Destination(width=5)
+  a1.out, a2.out -> b.in after delay
+}