ci: Make sure the Guix checkout is the one providing Cuirass proc.

Fixes <https://bugs.gnu.org/36378>.
Reported by Reza Alizadeh Majd <r.majd@pantherx.org>.

* build-aux/hydra/gnu-system.scm (find-current-checkout): New procedure.
(hydra-jobs): Use FIND-CURRENT-CHECKOUT to define CHECKOUT.  Pass it to the
inferior Guix as an extra argument whose key is 'superior-guix-checkout'.
* gnu/ci.scm (find-current-checkout): New procedure.
(hydra-jobs): Use FIND-CURRENT-CHECKOUT to define CHECKOUT.  This will return
'#f' if the current Guix is an inferior.  In that case, use the
'superior-guix-checkout' argument provided by the superior Guix.

1 files changed, 14 insertions, 8 deletions

diff --git a/gnu/ci.scm b/gnu/ci.scm
index f24049e772a..d6eb2d018f5 100644
--- a/gnu/ci.scm
+++ b/gnu/ci.scm
@@ -1,7 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2017 Jan Nieuwenhuizen <janneke@gnu.org>
-;;; Copyright © 2018 Clément Lassieur <clement@lassieur.org>
+;;; Copyright © 2018, 2019 Clément Lassieur <clement@lassieur.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -374,6 +374,17 @@ valid."
                              load-manifest)
                     manifests))))
 
+(define (find-current-checkout arguments)
+  "Find the first checkout of ARGUMENTS that provided the current file.
+Return #f if no such checkout is found."
+  (let ((current-root
+         (canonicalize-path
+          (string-append (dirname (current-filename)) "/.."))))
+    (find (lambda (argument)
+            (and=> (assq-ref argument 'file-name)
+                   (lambda (name)
+                     (string=? name current-root)))) arguments)))
+
 
 ;;;
 ;;; Hydra entry point.
@@ -396,13 +407,8 @@ valid."
       ((? string? str) (call-with-input-string str read))))
 
   (define checkout
-    ;; Extract metadata about the 'guix' checkout.  Its key in ARGUMENTS may
-    ;; vary, so pick up the first one that's neither 'subset' nor 'systems'.
-    (any (match-lambda
-           ((key . value)
-            (and (not (memq key '(systems subset)))
-                 value)))
-         arguments))
+    (or (find-current-checkout arguments)
+        (assq-ref arguments 'superior-guix-checkout)))
 
   (define commit
     (assq-ref checkout 'revision))