Hi, GHC 7.8 rc2 exhausts all memory on Bio.PDB.EventParser.PDBEventParser module in -O3 mode, but not in -O2 mode. The tail of -v3 input seems to indicate that it dies during SpecConstr phase. The module successfully compiled with relatively low memory use RAM since GHC 6.12, so I wonder why the memory use exploded with the most recent version. Since I am new to GHC core, may I have a hint what debugging information may help with this particular issue? *** SpecConstr: ==================== SpecConstr ==================== Result size of SpecConstr * I submitted the ticket: https://ghc.haskell.org/trac/ghc/ticket/8960 -- Best regards Michał