double M-x slime fails to open the second slime repl buffer

[informatimago]

To replicate, launch emacs:

• C-u M-x slime RET ccl RET
• C-u M-x slime RET sbcl RET # before slime-repl ccl opens.
  When both implementations have finished booting:

  * *inferior-lisp*<2>           42065 Comint:run       
  * *slime-repl ccl*                22 REPL             
  * *inferior-lisp*               8045 Comint:run       
 %  *GNU Emacs*                    990 Fundamental      
 %* *Messages*                   53928 Messages         
    *scratch*                      145 ELisp/d          
    *Shell Command Output*           0 Fundamental      
  * *Async Shell Command*           91 Shell:no process ~/
 %* *Warnings*                    1407 Special          
 %* *Compile-Log*                  136 Special          
 %* *Async-native-compile-log*     672 Fundamental      
  * *slime-events*                4825 Fundamental      

The second *inferior-lisp*<2> buffer with sbcl exists, and is ready (lisp prompt), but slime didn't create the *slime-repl sbcl* buffer.