- (coerce-to-condition datum
- arguments
- 'simple-error
- 'error)
- (make-condition 'simple-error
- :format-control "The assertion ~S failed."
- :format-arguments (list assertion)))))
+ (coerce-to-condition
+ datum arguments 'simple-error 'error)
+ (make-condition
+ 'simple-error
+ :format-control "~@<The assertion ~S failed~:[.~:; ~
+ with ~:*~{~{~S = ~S~}~^, ~}.~]~:@>"
+ :format-arguments (list assertion args-and-values)))))