..say I have this: SWGtk> (defcenum UpdateType :continuous :discontinous :delayed) ..then do: SWGtk> (foreign-enum-value 'UpdateType :not-valid) ..I get a meaningful message from CFFI: :not-valid is not defined as a keyword for enum type #<cffi::foreign-enum UpdateType>. ..very nice; as expected. But if I do: SWGtk> (foreign-funcall "someCFunction" UpdateType :not-valid) ..I get: The value nil is not of type (signed-byte 32). It is almost impossible to debug this because I cannot see any NIL anywhere. :not-valid is a constant here of course - but if it is in a variable: SWGtk> (foreign-funcall "someCFunction" UpdateType some-variable) ..`some-variable' _still_ doesn't contain NIL so I've been lost for quite some time here. -- Lars Rune Nøstdal http://nostdal.org/