The apache forrest installation within bigtop_toolchain is a bad idea.
apache-forrest is only needed AFAIK for "pig"
It has to be made r/w in bigtop_toolchain for all in order to work, since usage of forrest tries to write into forrest.
The solution is to download it in do-component-build, unpack and use it privately there.
In order to address security issues: Download from https and check md5sum