Ludovic Courtès <ludo@gnu.org> writes:

>> +                   (define (dynamic-link-substitute file lib input)
>> +                     (substitute* file
>> +                       (((string-append "dynamic-link \"" lib "\""))
>> +                        (string-append "dynamic-link \""
>> +                                       (assoc-ref inputs input)
>> +                                       "/lib/" lib "\""))))
>
> Patterns in ‘substitute*’ are supposed to be literals.
>
> Wouldn’t it work to do something like:
>
>   (substitute* file
>     (("dynamic-link \"lib[a-zA-Z]+\" _ libname)
>      (string-append ...)))
>
> ?
>

Yes, that's better.  Updated patch attached.