+ ;; Absolute file name of the module hierarchy. Since (gnu packages …) might
+ ;; live in a directory different from (guix), try to get the best match.
+ (letrec-syntax ((dirname* (syntax-rules ()
+ ((_ file)
+ (dirname file))
+ ((_ file head tail ...)
+ (dirname (dirname* file tail ...)))))
+ (try (syntax-rules ()
+ ((_ (file things ...) rest ...)
+ (match (search-path %load-path file)
+ (#f
+ (try rest ...))
+ (absolute
+ (dirname* absolute things ...))))
+ ((_)
+ #f))))
+ (try ("gnu/packages/base.scm" gnu/ packages/)
+ ("gnu/packages.scm" gnu/)
+ ("guix.scm"))))