hydra: Add jobs for all of '%final-inputs'.

* build-aux/hydra/gnu-system.scm (package->job): Create a 'base.' job
when PACKAGE is a member of BASE-PACKAGES.
(all-packages)[adjust]: New procedure.
Fold over %FINAL-INPUTS and add it to the result.

build-aux/hydra/gnu-system.scm

@@ -251,7 +251,8 @@ all its dependencies, and ready to be installed on non-GuixSD distributions.")
       "Return a job for PACKAGE on SYSTEM, or #f if this combination is not
 valid."
       (cond ((member package base-packages)
-             #f)
+             (package-job store (symbol-append 'base. (job-name package))
+                          package system))
             ((supported-package? package system)
              (let ((drv (package-derivation store package system
                                             #:graft? #f)))
@@ -263,7 +264,7 @@ valid."
 
 (define (all-packages)
   "Return the list of packages to build."
-  (fold-packages (lambda (package result)
+  (define (adjust package result)
     (cond ((package-replacement package)
            (cons* package                         ;build both
                   (package-replacement package)
@@ -272,7 +273,12 @@ valid."
            result)                                ;don't build it
           (else
            (cons package result))))
-                 '()
+
+  (fold-packages adjust
+                 (fold adjust '()                 ;include base packages
+                       (match (%final-inputs)
+                         (((labels packages _ ...) ...)
+                          packages)))
                  #:select? (const #t)))           ;include hidden packages