You need to fix all strict type warnings first.

$ ./pike -rT -rt -w lyskom_13004388.pike ... lyskom_13004388.pike:12: Warning: An expression type mixed cannot be assigned to a variable of type object. lyskom_13004388.pike:13: Warning: An expression type object cannot be assigned to a variable of type { File = object(implements 65627) }. 1

After fixing the warnings you get:

$ ./pike -mmaster.pike -rt -w lyskom_13004388.pike main(): Soft cast failed. Expected object, got int(1..1) lyskom_13004388.pike:12: /main()->main()