ant: 
  defaultProperties: 
    - installSource: 
       installers: 
          - "antFromApache" 
  installations: 
    - name: "Ant 1.10.5" 
      properties: 
        - installSource: 
            installers: 
             - antFromApache: 
                id: "1.10.5"

Caused by: io.jenkins.plugins.casc.ConfiguratorException: ant: Failed to construct instance of class hudson.tasks.Ant$AntInstallation. Constructor: public hudson.tasks.Ant$AntInstallation(java.lang.String,java.lang.String,java.util.List). Arguments: [java.lang.String, null, java.util.ArrayList] at io.jenkins.plugins.casc.impl.configurators.DataBoundConfigurator.tryConstructor(DataBoundConfigurator.java:149) at io.jenkins.plugins.casc.impl.configurators.DataBoundConfigurator.instance(DataBoundConfigurator.java:73) at io.jenkins.plugins.casc.BaseConfigurator.configure(BaseConfigurator.java:262) at io.jenkins.plugins.casc.impl.configurators.DataBoundConfigurator.check(DataBoundConfigurator.java:97) at io.jenkins.plugins.casc.BaseConfigurator.configure(BaseConfigurator.java:339) at io.jenkins.plugins.casc.BaseConfigurator.check(BaseConfigurator.java:282) at io.jenkins.plugins.casc.BaseConfigurator.configure(BaseConfigurator.java:347) at io.jenkins.plugins.casc.BaseConfigurator.check(BaseConfigurator.java:282) at io.jenkins.plugins.casc.ConfigurationAsCode.lambda$checkWith$6(ConfigurationAsCode.java:665) at io.jenkins.plugins.casc.ConfigurationAsCode.invokeWith(ConfigurationAsCode.java:627) ... 18 more Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at io.jenkins.plugins.casc.impl.configurators.DataBoundConfigurator.tryConstructor(DataBoundConfigurator.java:141) ... 27 more Caused by: java.lang.NullPointerException at hudson.tasks.Ant$AntInstallation.launderHome(Ant.java:371) at hudson.tasks.Ant$AntInstallation.<init>(Ant.java:359) ... 32 more