bug#40371: [R7RS] Guile does not accept library name parts that, are non-negative exact integers

I think I ran into this issue in a different place.


Guile does not support the ((library (foo bar) ...) form in cond-expand, 
so one way around it is to have (cond-expand (srfi-N ... ) ((library 
(srfi N)) ...) but in a situation where srfi-N is false Guile tries to 
evaluate the (library ... form and errors with (in the case of N being 180):

In procedure symbol->string: Wrong type argument in position 1 
(expecting symbol): 180


Here is the example code:

(import (scheme base)
         (scheme write))

(cond-expand
   (srfi-180
     (display "I has SRFI 180 :)")
     (newline))
   ((library (srfi 180))
     (display "I has SRFI 180 :)")
     (newline))
   (else
     (display "I do not has SRFI 180 :(")
     (newline)))

It also errors without the number there, saying (switching 180 -> foo):

no code for module (srfi foo)