gistfile1.txt

echo "
import system
 
type Bar[T] = ref object
  value: T
 
type types = int32|int64 # if I change this to just int32 or int64 it works (compiles)

# if I replace Bar everywhere with seq it also compiles fine 
proc Foo[T: Bar[types]](): T =
  when T is Bar: nil
 
discard Foo[Bar[int32]]()
" > a.nim

nim c a.nim

   SIGSEGV: Illegal storage access. (Attempt to read from nil?)