3 Constructors for `ForeignObj' not visible when checking `PrelGHC.CCallable' instance
4 (Try either importing ForeignObj non-abstractly or compile using -fno-prune-tydecls ..)
7 No instance for `PrelGHC.CCallable ForeignObj'
8 (arising from an argument in the _ccall_ to `c', namely `x' at cc002.hs:18)
11 No instance for `PrelGHC.CReturnable ForeignObj'
12 (arising from the result of the _ccall_ to `a' at cc002.hs:10)
15 Compilation had errors