gnu: libyajl: Actually run test suite.

* gnu/packages/web.scm (libyajl)[arguments]: Patch shebang in test suite.

gnu/packages/web.scm

@@ -10,7 +10,7 @@
 ;;; Copyright © 2015 Eric Dvorsak <eric@dvorsak.fr>
 ;;; Copyright © 2016 Sou Bunnbu <iyzsong@gmail.com>
 ;;; Copyright © 2016 Jelle Licht <jlicht@fsfe.org>
-;;; Copyright © 2016, 2017 Efraim Flashner <efraim@flashner.co.il>
+;;; Copyright © 2016, 2017, 2018 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2016 Rene Saavedra <rennes@openmailbox.org>
 ;;; Copyright © 2016 Ben Woodcroft <donttrustben@gmail.com>
 ;;; Copyright © 2016 Clément Lassieur <clement@lassieur.org>
@@ -752,6 +752,14 @@ (define-public libyajl
                (base32
                 "0nmcqpaiq4pv7dymyg3n3jsd57yhp5npxl26a1hzw3m3lmj37drz"))))
     (build-system cmake-build-system)
+    (arguments
+     '(#:phases
+       (modify-phases %standard-phases
+         (add-after 'patch-source-shebangs 'patch-tests
+           (lambda _
+             (substitute* "test/parsing/run_tests.sh"
+               (("`which echo`") (which "echo")))
+             #t)))))
     (home-page "https://lloyd.github.io/yajl/")
     (synopsis "C library for parsing JSON")
     (description