Android Studio: Where is the Compiler Error Output Window?

For Android Studio 3.1, select the icon below the Build one in the Build window.

https://i.stack.imgur.com/X5Gfr.png

By Android Studio 3.3 (possibly in 3.2.1), the icon has changed, though the location is the same:

https://i.stack.imgur.com/q9iRT.png

The build window should open when you run a build action (e.g. from the Build menu). If you don't see it, you can try the "Build" button along the bottom of the window (also visible in the above screenshots), or through the menus View → Tool Windows → Build.

---

This answer is outdated. For Android 3.1 Studio go to this answer

One thing you can do is deactivate the external build. To do so click on "compiler settings icon" in the "Messages Make" panel that appears when you have an error. You can also open the compiler settings by going to File -> Settings -> Compiler. (Thanx to @maxgalbu for this tip).

https://i.stack.imgur.com/DJw9e.png

Uncheck "Use External build"

https://i.stack.imgur.com/FyLEr.png

And you will see the errors in the console

EDIT: After returning to "internal build" again you may get some errors, you can solve them this way: Android Studio: disabling "External build" to display error output create duplicate class errors

---

It's really straightforward to set up! Just go to the Compiler settings at Android Studio 2.2.3 and set the --stacktrace command:

https://i.stack.imgur.com/VI0wp.png

Then run the app again

---

Are you on Windows? Launch cmd, find your project folder and run "gradlew build". This should already give you more output than the IDE, you can also use --info, --stacktrace and --debug there.

---

In my case I prefer to open the Terminal window on the bottom left, and run gradlew build --info :

https://i.stack.imgur.com/4N5yj.png

---

You can also see the error in the Build window by clicking on the toggle button.

https://i.stack.imgur.com/ui6SQ.png

---

For Android Studio v4.0

As others have mentioned, the "Messages" window that was evidently present in AS 3.* no longer exists in 4.0 (or else it's hidden very, very well). After wasting far too much time on this, I've found another way to view those compile errors:

Open your Gradle tool window. By default, it's on the right edge toward the top:

https://i.stack.imgur.com/vepRT.png

If you don't see it there, use View > Tool Windows > Gradle.

In the Gradle window, open your app's root option and run Tasks > build > build:

https://i.stack.imgur.com/4ZWut.png

The Run tool window should open automatically, where you'll see details about the cause of the build error:

https://i.stack.imgur.com/7s7Ir.png

If it doesn't open automatically, you can access it through View > Tool Windows > Run.

Hopefully that gives you all the info you need. If not though, try:

Go to File > Settings > Build, Execution, Deployment > Compiler. In the Command-line Options, add --scan.

https://i.stack.imgur.com/fse2n.png

Apply and OK, then try the Gradle build over again.

---

https://i.stack.imgur.com/0YIag.png

---

I am building on what Jorge recommended. Goto File->Settings->compiler.

Here you will see a field to add compiler options where you plug in --stacktrace

---

Run

gradlew --stacktrace 

in a terminal to see the full report

for me it was

Task :app:compileDebugJavaWithJavac FAILED javacTask: source release 1.8 requires target release 1.8

so i added

 compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

in app.gradle file / android and the build completed successfully

---

Just click on the "Build" node in the Build Output

https://i.stack.imgur.com/YamGB.png

From some reason the "Compilation failed" node just started being automatically selected and for that the description window is very unhelpful.

---

If you are in android studio 3.1, Verify if file->Project Structure -> Source compatibility is empty. it should not have 1.8 set.

then press ok, the project will sync and error will disappear.

---

In my case i had a findViewById reference to a view i had deleted in xml

if you are running AS 3.1 and above:

go to Settings > Build, Execution and Deployment > compiler add --stacktrace to the command line options, click apply and ok At the bottom of AS click on Console/Build(If you use the stable version 3.1.2 and above) expand the panel and run your app again.

you should see the full stacktrace in the expanded view and the specific error.

---

after the convert android to androidx.

change Import library problem will sol. Like this:

import androidx.appcompat.widget.Toolbar;  <<  like this

import androidx.annotation.NonNull; << like this

import androidx.appcompat.app.ActionBarDrawerToggle; << like this

import androidx.drawerlayout.widget.DrawerLayout; << like this

import androidx.recyclerview.widget.RecyclerView; << like this

import androidx.appcompat.app.AppCompatActivity; << like this

---

Follow these steps!

Go to File Then click on Settings Then under "Build, Execution, Deployment" go to Compiler Add this in "Command-line Options" and press OK Now normally run your test/app again and when you will encounter error this time, you will see highlighted messages like this :

Clicking on "Run with --scan" or "Run with --stacktrace" will give error in more detail.

---

I solved this error "Compilation failed to see the compiler error output for details"

The solution is very Simple: Add in a Gradle below a line of code

implementation 'com.google.android.gms:play-services-ads:15.0.0'

---