JetBrains/intellij-community · error · BuildException

Selected InputHandler should be used by Intellij IDEA

Error message

Selected InputHandler should be used by Intellij IDEA

What it means

IdeaInputHandler communicates with the IDE through IdeaAntLogger2.ourErr, a SegmentedOutputStream that IDEA installs when it launches Ant. If that static field is null, the handler is running outside an IDEA-spawned build process (no logger initialized), so it throws BuildException("Selected InputHandler should be used by Intellij IDEA").

Source

Thrown at java/java-runtime/src/com/intellij/rt/ant/execution/IdeaInputHandler.java:21

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.input.InputHandler;
import org.apache.tools.ant.input.InputRequest;
import org.apache.tools.ant.input.MultipleChoiceInputRequest;

import java.io.IOException;
import java.util.List;

public class IdeaInputHandler implements InputHandler {
  @Override
  public void handleInput(InputRequest request) throws BuildException {
    final String prompt = request.getPrompt();
    if (prompt == null) {
      throw new BuildException("Prompt is null");
    }
    final SegmentedOutputStream err = IdeaAntLogger2.ourErr;
    if (err == null) {
      throw new BuildException("Selected InputHandler should be used by Intellij IDEA");
    }
    final PacketWriter packet = PacketFactory.ourInstance.createPacket(AntLoggerConstants.INPUT_REQUEST);
    packet.appendLimitedString(prompt);
    packet.appendLimitedString(request.getDefaultValue());
    if (request instanceof MultipleChoiceInputRequest) {
      @SuppressWarnings("unchecked") 
      List<String> choices = ((MultipleChoiceInputRequest)request).getChoices();
      if (choices != null && !choices.isEmpty()) {
        int count = choices.size();
        packet.appendLong(count);
        for (String choice : choices) {
          packet.appendLimitedString(choice);
        }
      }
      else {
        packet.appendLong(0);
      }
    }

View on GitHub (pinned to be881553f2)

Solutions

1. Remove the -inputhandler IdeaInputHandler flag (and related IDEA Ant runtime classpath entries) when running Ant outside IntelliJ.
2. Run the build from the IDEA Ant tool window so the IDE initializes IdeaAntLogger2 before any <input> task.
3. In CI, use the DefaultInputHandler or a property-file driven input handler instead of the IDE one.

Example fix

# before
ant -inputhandler com.intellij.rt.ant.execution.IdeaInputHandler build # outside IDEA -> throws

# after
ant build # default input handler works standalone

# only use the handler inside IDEA-launched builds:
ant build # drop -inputhandler ...IdeaInputHandler when standalone

When it happens

Trigger: Manually running Ant with -inputhandler com.intellij.rt.ant.execution.IdeaInputHandler from a plain command line, or a build process where IdeaAntLogger2 was never initialized (IDE launched Ant through a different path).

Common situations: Copying the IDEA-generated Ant command line to a terminal/CI; scripts that reuse IDEA's Ant runtime jars; running the same build.xml under a standalone Ant distribution while keeping IDEA-specific handler settings.

Related errors

• \nThe version of the executed Ant is not compatible with the
• Prompt is null
• Invalid input: {input}
• Row index: %d. Error during nested table row creation: row i
• Column number: %d. Error during retrieving value from nested

AI-assisted analysis of JetBrains/intellij-community@be881553f2 (2026-08-14). Data as JSON: /api/errors/a6c1609b5ea7f46d. Report an issue: GitHub.