Spock extension's source-jar is empty in Maven Central #2280
Description
spock-1.12.4-sources.jar is empty (has no .java/.groovy files in it):
$ unzip -l spock-1.12.4-sources.jar
Archive: spock-1.12.4-sources.jar
Length Date Time Name
--------- ---------- ----- ----
0 2019-11-29 11:08 META-INF/
25 2019-11-29 11:08 META-INF/MANIFEST.MF
0 2019-11-29 11:01 org/
0 2019-11-29 11:01 org/testcontainers/
0 2019-11-29 11:01 org/testcontainers/spock/
--------- -------
25 5 files