diff --git a/guix/derivations.scm b/guix/derivations.scm index 480a65c78b1..f6d6f7db25b 100644 --- a/guix/derivations.scm +++ b/guix/derivations.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès +;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès ;;; Copyright © 2016, 2017 Mathieu Lirzin ;;; ;;; This file is part of GNU Guix. @@ -240,6 +240,13 @@ the store." "Return a list of inputs, such that when INPUTS contains the same DRV twice, they are coalesced, with their sub-derivations merged. This is needed because Nix itself keeps only one of them." + (define (find pred lst) ;inlinable copy of 'find' + (let loop ((lst lst)) + (match lst + (() #f) + ((head . tail) + (if (pred head) head (loop tail)))))) + (fold (lambda (input result) (match input (($ (= derivation-file-name path) sub-drvs)