On Sun, Jan 15, 2017 at 10:53:02AM +0100, David Craven wrote:
     > will erroneously return #t when (file-system-mount-point fs) evaluates
     > to "/gn"  and (%store-directory) to "/gnu/store".  Will it not???
     
     The trick is to revert the arguments:
     
     (string-prefix? (%store-directory) (file-system-mount-point fs))

No that will also be wrong.

(string-prefix? "/gnu/store" "/gnu") => #f

I think the procedure  I wrote does it correctly.

J'

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