Error:Execution failed for task ':app:dexDebug' - debugging

Question

I was trying to add Google Maps service in emulator in Android Studio for Mac.
I used this to add google play services in my emulator and now I am getting this error.
I also added Google play jar in "libs"
Build error
Error:Execution failed for task ':app:dexDebug'.
> com.android.ide.common.internal.LoggedErrorException: Failed to run command:
/Applications/Android Studio.app/sdk/build-tools/21.0.0/dx --dex --num-threads=4 --output /Users/BrijD/Desktop/Final_maps/app/build/intermediates/dex/debug /Users/BrijD/Desktop/Final_maps/app/build/intermediates/classes/debug /Users/BrijD/Desktop/Final_maps/app/build/intermediates/dependency-cache/debug /Users/BrijD/Desktop/Final_maps/app/build/intermediates/pre-dexed/debug/classes-0fd5fdfe526893278be8c195ce134eaf1d9f1e86.jar /Users/BrijD/Desktop/Final_maps/app/build/intermediates/pre-dexed/debug/classes-1c1ab6ce82c35aba8a1d88f2624cf1338444a247.jar /Users/BrijD/Desktop/Final_maps/app/build/intermediates/pre-dexed/debug/classes-3fa4a9ac8fa2216bad3a7f16c9a774b0dc355d43.jar /Users/BrijD/Desktop/Final_maps/app/build/intermediates/pre-dexed/debug/classes-8f6dc1447c1249308d36a8f93d1adf33837f8664.jar /Users/BrijD/Desktop/Final_maps/app/build/intermediates/pre-dexed/debug/internal_impl-21.0.0-fd4beb3682904051af27f723f6ba9423e4f00b8a.jar /Users/BrijD/Desktop/Final_maps/app/build/intermediates/pre-dexed/debug/support-annotations-21.0.0-ee576f91b45a6538d4156fc6e674b6f65034f74e.jar
Error Code:
2
Output:
UNEXPECTED TOP-LEVEL EXCEPTION:
com.android.dex.DexException: Multiple dex files define Lcom/google/android/gms/actions/ReserveIntents;
at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:596)
at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:554)
at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:535)
at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)
at com.android.dx.merge.DexMerger.merge(DexMerger.java:189)
at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:454)
at com.android.dx.command.dexer.Main.runMonoDex(Main.java:302)
at com.android.dx.command.dexer.Main.run(Main.java:245)
at com.android.dx.command.dexer.Main.main(Main.java:214)
at com.android.dx.command.Main.main(Main.java:106)
AndroidMainefest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="dormroomdevelopers.final_maps" >
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MyActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MapsActivity">
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="*****************************"/>
</activity>
<meta-data android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
</application>
</manifest>
app build.gradle
apply plugin: 'com.android.application'
android {
compileSdkVersion 21
buildToolsVersion "21"
defaultConfig {
applicationId "dormroomdevelopers.final_maps"
minSdkVersion 18
targetSdkVersion 21
versionCode 1
versionName "1.0"
}
buildTypes {
release {
runProguard false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.google.android.gms:play-services:6.5.87'
compile 'com.google.android.gms:play-services-maps:6.5.+'
}
proguard-rules.pro
-keep class * extends java.util.ListResourceBundle {
protected Object[][] getContents();
}
-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
public static final *** NULL;
}
-keepnames #com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
#com.google.android.gms.common.annotation.KeepName *;
}
-keepnames class * implements android.os.Parcelable {
public static final ** CREATOR;
}

Answer 1

This error in general means that you've tried to link in the same class to your project more than once, which isn't allowed. The offending class is com/google/android/gms/actions/ReserveIntents, which is in the Google Play Services library.
The problem is in your dependencies:
compile 'com.google.android.gms:play-services:6.5.87'
compile 'com.google.android.gms:play-services-maps:6.5.+'
These are redundant. The play-services:6.5.87 includes everything, and if you have that, you don't need the play-services-maps:6.5.+ dependency. The reason you might want the latter one is if your project gets too big and you need to pare down to a smaller, more granular Play Services where you only include what you need.
To make life easier, I'd recommend going with the first one, and if you run into compile problems (such as the most classic one, Unable to execute dex: method ID not in [0, 0xffff]: 65536, though it takes different forms), then you can go to the latter format.
There's more documentation on how to use the big library and the smaller libraries at http://developer.android.com/google/play-services/setup.html and http://developer.android.com/google/play-services/setup.html#split

Answer 2

It seems you have a jar file or a lib appearing multiple times. So, remove the .jar file from the lib folder Build> Rebuild Must work.