Propagate exceptions from conjure

.gitignore

@@ -38,6 +38,7 @@ fileeditor
 *.iws
 .idea/
 out/
+.profileconfig.json
 
 # Eclipse/IntelliJ APT
 generated_src/

changelog/@unreleased/pr-1369.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Propagate exceptions from conjure
+  links:
+  - https://github.com/palantir/gradle-conjure/pull/1369

gradle-conjure/src/main/java/com/palantir/gradle/conjure/ConjureRunnerResource.java

@@ -83,7 +83,7 @@ static ConjureRunner createNewRunner(File executable) throws IOException {
             URLClassLoader classLoader =
                     new ChildFirstUrlClassLoader(info.classpathUrls(), ConjureRunnerResource.class.getClassLoader());
             try {
-                Optional<Method> mainMethod = getMainMethod(classLoader, info.mainClass());
+                Optional<Method> mainMethod = getInProcessOrMainMethod(classLoader, info.mainClass());
                 if (mainMethod.isPresent()) {
                     classLoaderMustBeClosed = false;
                     return new InProcessConjureRunner(executable, mainMethod.get(), classLoader);
@@ -97,6 +97,19 @@ static ConjureRunner createNewRunner(File executable) throws IOException {
         return new ExternalProcessConjureRunner(executable);
     }
 
+    private static Optional<Method> getInProcessOrMainMethod(URLClassLoader classLoader, String mainClassName) {
+        try {
+            Class<?> mainClass = classLoader.loadClass(mainClassName);
+            return Optional.of(mainClass.getMethod("inProcessExecution", String[].class));
+        } catch (ClassNotFoundException e) {
+            log.warn("Failed to get main method for class {}", mainClassName, e);
+            return Optional.empty();
+        } catch (NoSuchMethodException e) {
+            log.debug("Falling back to using the main method", mainClassName, e);
+            return getMainMethod(classLoader, mainClassName);
+        }
+    }
+
     private static Optional<Method> getMainMethod(URLClassLoader classLoader, String mainClassName) {
         try {
             ClassFileLocator locator = new ClassFileLocator.ForUrl(classLoader.getURLs());
@@ -184,7 +197,6 @@ public void invoke(Project project, String failedTo, List<String> unloggedArgs,
                     .addAll(unloggedArgs)
                     .addAll(loggedArgs)
                     .build();
-
             try {
                 String[] args = combinedArgs.toArray(new String[] {});
                 mainMethod.invoke(null, new Object[] {args});
@@ -201,7 +213,9 @@ public void invoke(Project project, String failedTo, List<String> unloggedArgs,
                     // Exit status zero, we're good to go!
                 } else {
                     throw new RuntimeException(
-                            String.format("Failed to %s. The command '%s' failed.", failedTo, combinedArgs), t);
+                            String.format(
+                                    "%s\n\nFailed to %s. The command '%s' failed.", rootCause, failedTo, combinedArgs),
+                            t);
                 }
             }
         }

gradle-conjure/src/test/groovy/com/palantir/gradle/conjure/ConjureBasePluginIntegrationSpec.groovy

@@ -16,6 +16,8 @@
 
 package com.palantir.gradle.conjure
 
+import org.junit.internal.Throwables
+
 import java.nio.file.Files
 import nebula.test.IntegrationSpec
 import nebula.test.functional.ExecutionResult
@@ -95,7 +97,8 @@ class ConjureBasePluginIntegrationSpec extends IntegrationSpec {
         file('src/main/conjure/api.yml') << "foo"
 
         then:
-        runTasksWithFailure('compileIr')
+        ExecutionResult result = runTasksWithFailure('compileIr')
+        com.google.common.base.Throwables.getRootCause(result.failure).message.contains "vjf"
     }
 
     def 'compileIr can get results from the build cache'() {