When one Gradle installation is defined in the the global Jenkins configuration and a job definition config.xml specifies an empty <gradleName/> element, the Gradle build fails with the following error:

java.io.IOException: Cannot run program "gradle" (in directory "/var/lib/jenkins/jobs/<job>/workspace"): error=2, No such file or directory

Specifying a Gradle installation name allows the build to succeed. Is there a name that can be given to an installation to have it be recognized as the "(Default)"?