Hi again - I have the following C function definition (from RabbitMQ C client): typedef enum amqp_response_type_enum_ { AMQP_RESPONSE_NONE = 0, AMQP_RESPONSE_NORMAL, AMQP_RESPONSE_LIBRARY_EXCEPTION, AMQP_RESPONSE_SERVER_EXCEPTION } amqp_response_type_enum; typedef struct amqp_rpc_reply_t_ { amqp_response_type_enum reply_type; amqp_method_t reply; int library_errno; } amqp_rpc_reply_t; /* Opaque struct. */ typedef struct amqp_connection_state_t_ *amqp_connection_state_t; typedef enum amqp_sasl_method_enum_ { AMQP_SASL_METHOD_PLAIN = 0 } amqp_sasl_method_enum; extern amqp_rpc_reply_t amqp_login(amqp_connection_state_t state, char const *vhost, int channel_max, int frame_max, int heartbeat, amqp_sasl_method_enum sasl_method, ...); which I hand-translated to the following CFFI statements: (defcenum amqp-sasl-method-enum (:AMQP-SASL-METHOD-PLAIN 0)) (defcenum amqp-response-type-enum (:AMQP-RESPONSE-NONE 0) :AMQP-RESPONSE-NORMAL :AMQP-RESPONSE-LIBRARY-EXCEPTION :AMQP-RESPONSE-SERVER-EXCEPTION) (defcstruct amqp-rpc-reply-struct (reply-type amqp-response-type-enum) (reply amqp-method-t) (library-errno :int)) (defctype amqp-rpc-reply-t amqp-rpc-reply-struct) (defctype amqp-connection-state-t :pointer) (defcfun ("amqp_login" %amqp-login) amqp-rpc-reply-t (state amqp-connection-state-t) (vhost :string) (channel-max :int) (frame-max :int) (heartbeat :int) (sasl-method amqp-sasl-method-enum) &rest) ;; varargs ! You still there ? ;-) Good. Now for my "issue": Calling the C function amqp_login function as follows: (defparameter *hostname* "192.168.2.121") (defparameter *port* 5672) (defparameter *user* "ccag.pib") (defparameter *password* "ccag.pib") (defparameter *vhost* "/ccag/pib") (let* ((conn (%amqp-new-connection)) (sockfd (%amqp-open-socket *hostname* *port*))) (%amqp-login conn *vhost* 0 131072 0 :AMQP-SASL-METHOD-PLAIN :string *user* :string *password*) ... results in the following output from the C function amqp_login (which I instrumented): *** AMQP_LOGIN sees: -> state = 0x64034010 -> vhost = (null) -> channel_max = 131072 -> frame_max = 0 -> heartbeat = 0 -> sasl_method = 1677934672 Hmmmmmm - let's see: vhost .........: Not good. Should be "/ccag/pib". channel_max ...: Not good. Should be 0. frame_max .....: Not good. Should be 131072. sasl_method ...: Not good. Should be 0. What am I doing wrong here? By now I'm trying to figure this out for more than 10 hours and I am at a loss here.... Any help/ ideas really appreciated! TIA!!! Frank