piResultTys1
Error provoked by attached H98 program (which is generated by a program); compiles fine without optimizations; compilation with -O2 crashes:
$ ghc --make -O2 FactorialSequ.lhs
[1 of 1] Compiling FactorialSequ ( FactorialSequ.lhs, FactorialSequ.o )
ghc: panic! (the 'impossible' happened)
(GHC version 8.0.2 for x86_64-unknown-linux):
piResultTys1
Sequ7 t_a2zl
[a_a2zm]