As Yennick said in that other thread: you should probably add
the theme as an external dependency when compiling the
library, and use the theme dependency scope in the
main project that leverages this library.
dependency management section in the docs for more
Unfortunately it's been years since I've compiled any Flex
If adding the halo.swc as an external dep doesn't help, I'm not
sure how we can investigate without looking into the code.
I would try to recreate what that ANT build is doing on the
command line (so just compc and whatever flags it needs to get it
to compile your library). In the end, GradleFx is just a wrapper
around Flex' command line tools, so from there you should be able
to figure out how to convert it (or post your command here so we
can help you).