When the shadowJar task encounters too many entries to zip32, it shows a generic error message about enabling zip64, but doesn’t actually provide the configuration snippet needed to accomplish this.
The error message links to a doc page, which also neglects to mention the snippet needed.
FYI, it’s:
shadowJar {
zip64 true
}
It might not look like much, but it can often be difficult to guess these sorts of valid configuration syntaxes.