Implementation attributes are missing from Maven shade transformer configuration in spring-boot-starter-parent

[pse-sonic]

Hi,
I've noticed that the spring-boot-starter-parent probably contains an invalid configuration of the maven-shade-plugin. There is an "empty" transformer delegate.transformer('') which causes a NoSuchMethodException in some cases. The configuration of the transformers has been changed from 2.2.x to 2.3.x.

[wilkinsona]

Can you please provide some more information about the NoSuchMethodException? There's an accidental empty <transformer></transformer> in the configuration, but I doubt that would cause a NoSuchMethodException.

[pse-sonic]

My fault - The empty transformer is also a part of the 2.2.x configuration of the shade plugin.

I figured out that the problem is caused by the missing attribute implementation for all listed transformers. If I override the shade plugin configuration and add these attributes to the transformers (based on the 2.2.x configuration) the problem is solved.