I did free Debian Jesse builds for Pony using llvm 3.7 package and llvm 3.8 package and had no issue with either debug or release builds.
Which Jesse are you using?
Note, I started from a completely clean Jesse install and followed the steps that are waiting to be merged into master via PR 650. Java training in chennai | Android training in chennai | Oracle dba Training in Chennai | Python Training in chennai