Make sure StepFailedException includes full description. Summary: I saw this while developing and decided the error message could have been more helpful. Test Plan: Sandcastle builds.

diff --git a/src/com/facebook/buck/step/StepFailedException.java b/src/com/facebook/buck/step/StepFailedException.java
index 2a8785d..38bc94c 100644
--- a/src/com/facebook/buck/step/StepFailedException.java
+++ b/src/com/facebook/buck/step/StepFailedException.java

@@ -37,12 +37,12 @@
       Optional<BuildTarget> buildTarget) {
     String message;
     if (buildTarget.isPresent()) {
-      message = String.format("%s failed on step \"%s\" with exit code %d",
+      message = String.format("%s failed with exit code %d:\n%s",
           buildTarget.get().getFullyQualifiedName(),
-          step.getShortName(),
-          exitCode);
+          exitCode,
+          step.getDescription(context));
     } else {
-      message = String.format("Failed with %d: %s",
+      message = String.format("Failed with exit code %d:\n%s",
           exitCode,
           step.getDescription(context));
     }

diff --git a/test/com/facebook/buck/shell/GenruleFailingCommandIntegrationTest.java b/test/com/facebook/buck/shell/GenruleFailingCommandIntegrationTest.java
index 50c05ef..8597813 100644
--- a/test/com/facebook/buck/shell/GenruleFailingCommandIntegrationTest.java
+++ b/test/com/facebook/buck/shell/GenruleFailingCommandIntegrationTest.java

@@ -49,6 +49,7 @@
 
     // We make sure that we failed for the right reason.
     assertThat(buildResult.getStderr(),
-        containsString("BUILD FAILED: //:fail failed on step \"genrule\" with exit code 1"));
+        containsString("BUILD FAILED: //:fail failed with exit code 1:\n" +
+        		"/bin/bash -e -c 'false; echo >&2 hi'"));
   }
 }

diff --git a/test/com/facebook/buck/step/BUCK b/test/com/facebook/buck/step/BUCK
index b5c2c4a..9366392 100644
--- a/test/com/facebook/buck/step/BUCK
+++ b/test/com/facebook/buck/step/BUCK

@@ -31,6 +31,7 @@
     '//lib:guava',
     '//lib:junit',
     '//src/com/facebook/buck/event:event',
+    '//src/com/facebook/buck/model:model',
     '//src/com/facebook/buck/step:step',
     '//src/com/facebook/buck/util:io',
     '//src/com/facebook/buck/util:util',

diff --git a/test/com/facebook/buck/step/StepFailedExceptionTest.java b/test/com/facebook/buck/step/StepFailedExceptionTest.java
new file mode 100644
index 0000000..2bf542b
--- /dev/null
+++ b/test/com/facebook/buck/step/StepFailedExceptionTest.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2013-present Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License. You may obtain
+ * a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.facebook.buck.step;
+
+import static org.junit.Assert.assertEquals;
+
+import com.facebook.buck.model.BuildTarget;
+import com.google.common.base.Optional;
+
+import org.junit.Test;
+
+public class StepFailedExceptionTest {
+
+  @Test
+  public void testCreateForFailingStepWithBuildTarget() {
+    final int exitCode = 17;
+    Step step = new FakeStep("cp", "cp foo bar", exitCode);
+    ExecutionContext context = TestExecutionContext.newInstance();
+    BuildTarget buildTarget = new BuildTarget("//foo", "bar");
+    StepFailedException exception = StepFailedException.createForFailingStep(
+        step, context, exitCode, Optional.of(buildTarget));
+
+    assertEquals(step, exception.getStep());
+    assertEquals(exitCode, exception.getExitCode());
+    assertEquals("//foo:bar failed with exit code 17:\ncp foo bar", exception.getMessage());
+  }
+
+  @Test
+  public void testCreateForFailingStepWithoutBuildTarget() {
+    final int exitCode = 17;
+    Step step = new FakeStep("cp", "cp foo bar", exitCode);
+    ExecutionContext context = TestExecutionContext.newInstance();
+    StepFailedException exception = StepFailedException.createForFailingStep(
+        step, context, exitCode, Optional.<BuildTarget>absent());
+
+    assertEquals(step, exception.getStep());
+    assertEquals(exitCode, exception.getExitCode());
+    assertEquals("Failed with exit code 17:\ncp foo bar", exception.getMessage());
+  }
+}