--> ABCL:       ; Compiling /home/linus/a.lisp ...
; (DEFCLASS BLA ...)
; (M)



 --> Allegro:    ; Loading /tmp/cl-all.lisp
;   Loading /home/linus/b.lisp
;;; Compiling file /home/linus/a.lisp


ERROR: No class named: BLA.
; Initial Lisp Listener will be killing processes: 
;; processes killed
; Exiting

 --> CLisp:      
(#<STANDARD-CLASS BLA> #<STANDARD-CLASS BLA> T) 

 --> CMUCL:      
; Compilation unit aborted.



ERROR: (during macroexpansion)


 --> ECL:        ;;; Loading "/tmp/cl-all.lisp"
;;; Loading "/home/linus/b.lisp"
;;; Loading #P"/usr/local/lib/ecl-16.1.3/cmp.fas"
;;;
;;; Compiling /home/linus/a.lisp.
;;; OPTIMIZE levels: Safety=2, Space=0, Speed=3, Debug=0
;;;
;;; End of Pass 1.
;;; Finished compiling /home/linus/a.lisp.
;;;
;;; Loading "/home/linus/a.fas"

(#<The STANDARD-CLASS COMMON-LISP-USER::BLA>
 #<The STANDARD-CLASS COMMON-LISP-USER::BLA> T) 
 --> SBCL:       This is SBCL 1.4.14, an implementation of ANSI Common Lisp.
More information about SBCL is available at <http://www.sbcl.org/>.

SBCL is free software, provided as is, with absolutely no warranty.
It is mostly in the public domain; some portions are provided under
BSD-style licenses.  See the CREDITS and COPYING files in the
distribution for more information.
; compiling file "/home/linus/a.lisp" (written 14 FEB 2019 12:56:58 PM):
; compiling (DEFCLASS BLA ...)
; compiling (M)
; file: /home/linus/a.lisp
; in:
;      MACROLET ((M (&ENVIRONMENT ENV) (SETF *TMP* (FIND-CLASS 'BLA ENV)) NIL))
;     (M)
; 
; caught ERROR:
;   (during macroexpansion of (M))
;   There is no class named COMMON-LISP-USER::BLA.
; 
; compilation unit finished
;   caught 1 ERROR condition


; wrote /home/linus/a.fasl
; compilation finished in 0:00:00.004
While evaluating the form starting at line 2, column 0
  of #P"/home/linus/b.lisp":
While evaluating the form starting at line 1, column 0
  of 

ERROR: Execution of a form compiled with errors.
Form:
  (M)
Compile-time error:
  (during macroexpansion of (M))
There is no class named COMMON-LISP-USER::BLA.#P"/tmp/cl-all.lisp":