Catch the case where the compilation fails because of a NoClassDefFoundError.

It may happen when an annotation processor is present but has a dependency which is missing.

Author: desruisseaux

src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java

@@ -1368,12 +1368,13 @@ private void compile(final JavaCompiler compiler, final Options configuration) t
         if (!executor.applyIncrementalBuild(this, configuration)) {
             return;
         }
-        Exception failureCause = null;
+        Throwable failureCause = null;
         final var compilerOutput = new StringWriter();
         boolean success;
         try {
             success = executor.compile(compiler, configuration, compilerOutput);
-        } catch (Exception e) {
+        } catch (Exception | NoClassDefFoundError e) {
+            // `NoClassDefFoundError` may happen if a dependency of an annotation processor is missing.
             success = false;
             failureCause = e;
         }

src/main/java/org/apache/maven/plugin/compiler/DiagnosticLogger.java

@@ -181,7 +181,7 @@ public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
      *
      * @param cause if compilation failed with an exception, the cause
      */
-    Optional<String> firstError(Exception cause) {
+    Optional<String> firstError(Throwable cause) {
         return Optional.ofNullable(cause != null && firstError == null ? cause.getMessage() : firstError);
     }
 

src/main/java/org/apache/maven/plugin/compiler/ToolExecutor.java

@@ -654,6 +654,7 @@ public boolean compile(final JavaCompiler compiler, final Options configuration,
                 fileManager.setLocationFromPaths(StandardLocation.CLASS_OUTPUT, Set.of(outputForRelease));
                 latestOutputDirectory = outputForRelease;
                 unit.outputForRelease = outputForRelease;
+                sourcesForDebugFile.add(unit);
                 /*
                  * Compile the source files now. The following loop should be executed exactly once.
                  * It may be executed twice when compiling test classes overwriting the `module-info`,
@@ -681,7 +682,6 @@ public boolean compile(final JavaCompiler compiler, final Options configuration,
                     if (workaroundNeedsClose) {
                         workaround.close();
                     }
-                    sourcesForDebugFile.add(unit);
                     if (!success) {
                         break compile;
                     }