docs-reference build fails due to extlink.spec.version property not set

java.lang.ExceptionInInitializerError
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.ja
va:62)
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccesso
rImpl.java:45)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:488)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.taglets.TagletManager.addCustomTag(TagletManager.java:26
3)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.BaseConfiguration.initTagletManager(BaseConfiguration.ja
va:786)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.BaseConfiguration.finishOptionSettings0(BaseConfiguratio
n.java:726)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.HtmlConfiguration.finishOptionSettings0(HtmlConfigu
ration.java:867)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.BaseConfiguration.setOptions(BaseConfiguration.java:747)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.AbstractDoclet.startGeneration(AbstractDoclet.java:204)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.AbstractDoclet.run(AbstractDoclet.java:117)
        at jdk.javadoc/jdk.javadoc.doclet.StandardDoclet.run(StandardDoclet.java:72)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.parseAndExecute(Start.java:581)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:430)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:343)
        at jdk.javadoc/jdk.javadoc.internal.tool.Main.execute(Main.java:63)
        at jdk.javadoc/jdk.javadoc.internal.tool.Main.main(Main.java:52)
Caused by: java.lang.RuntimeException: extlink.spec.version property not set
        at build.tools.taglet.ExtLink.<clinit>(ExtLink.java:60)
        ... 17 more