Fail Task

## Fail

### Description

Exits the current build (just throwing a BuildException), optionally printing additional information.

The message of the Exception can be set via the message attribute or character data nested into the element.

### Parameters

Attribute | Description | Required
message | A message giving further information on why the build exited | No
if | Only fail if a property of the given name exists in the current project | No
unless | Only fail if a property of the given name doesn't exist in the current project | No
status | Exit using the specified status code; assuming the generated Exception is not caught, the JVM will exit with this status. Since Ant 1.6.2 | No

### Parameters specified as nested elements

As an alternative to the if/unless attributes, conditional failure can be achieved using a single nested `<condition>` element, which should contain exactly one core or custom condition. For information about conditions, see here.
Since Ant 1.6.2

### Examples

      <fail/>

will exit the current build with no further information given.

    BUILD FAILED

    build.xml:4: No message

      <fail message="Something wrong here."/>

will exit the current build and print something like the following to wherever your output goes:

    BUILD FAILED

    build.xml:4: Something wrong here.

      <fail>Something wrong here.</fail>

will give the same result as above.

      <fail unless="thisdoesnotexist"/>

will exit the current build and print something like the following to wherever your output goes:

    BUILD FAILED

    build.xml:2: unless=thisdoesnotexist

Using a condition to achieve the same effect:

      <fail>
         <condition>
           <not>
             <isset property="thisdoesnotexist"/>
           </not>
         </condition>
       </fail>

Output:

    BUILD FAILED

    build.xml:2: condition satisfied

    <fail message="Files are missing.">
        <condition>
            <not>
                <resourcecount count="2">
                    <fileset id="fs" dir="." includes="one.txt,two.txt"/>
                </resourcecount>
            </not>
        </condition>
    </fail>

Will check that both files one.txt and two.txt are present otherwise the build will fail.