See error below.
Apparently bin is not needed in the end, but one has to create it manually to push through ant-based build.
$ ant
Buildfile: /Users/laemmel/github/softlang/megalib/checker/build.xml
create_run_jar:
BUILD FAILED
/Users/laemmel/github/softlang/megalib/checker/build.xml:9: /Users/laemmel/github/softlang/megalib/checker/bin does not exist.
/cc @AndrEm12 @MarcelH91
See error below. Apparently bin is not needed in the end, but one has to create it manually to push through ant-based build.