Cannot generalise these overloadings (in a _ccall_):
    `PrelGHC.CReturnable a' arising from the result of the _ccall_ to `f' at cc004.hs:8

Cannot generalise these overloadings (in a _ccall_):
    `PrelGHC.CReturnable a' arising from the result of the _ccall_ to `f' at cc004.hs:15