Java 21 throws warning with idiomatic Freebuilder usage

[rohlandm]

Hello,

while preparing a codebase for the migration to Java 21, we noticed that when you use Freebuilder with default values as described in the README

public Builder() {
      // Set defaults in the builder constructor.
      description("Indescribable");
}

the Java 21 compiler now throws a warning, failing the compilation if the -Werror flag is set.

This can be suppressed with @SuppressWarnings("this-escape"), but having a cleaner solution would be preferable.

[alicederyn]

What happens if you add an explicit super. before the method call?

[rohlandm]

It still throws the warning, as it is still a call to a overwritable method from the constructor

[alicederyn]

That seems like a bug, since it's not overwriteable if you call the super method.

[rohlandm]

🤔 strange. In the meantime, a workaround would be to not set the defaults in the constructor directly but in a static builder() method (subsequently decreasing the constructor's visibility)

[alicederyn]

I'll leave this open in case anyone has any other advice