gnu: facter: Embed more absolute references.

* gnu/packages/admin.scm (facter)[arguments]: Rename the
‘embed-iproute-reference’ phase to ‘embed-absolute-references’ and make
it generic.  Implicit inputs like coreutils are captured.  References
depend on what's found, not a hard-coded list.
[inputs]: Add dmidecode, inetutils, pciutils, and util-linux.

gnu/packages/admin.scm

@@ -455,7 +455,8 @@ graphs and can export its output to different formats.")
                 "0bab3by926gavbhkvp0in82vim575ybj8z6av3b12jdvla1s9rmz"))))
     (build-system ruby-build-system)
     (arguments
-     `(#:phases (modify-phases %standard-phases
+     `(#:phases
+       (modify-phases %standard-phases
          (add-after 'unpack 'delete-facter-ng-gemspec
            (lambda _
              ;; XXX: ruby-build-system incorrectly finds
@@ -466,15 +467,14 @@ graphs and can export its output to different formats.")
              ;; facter-ng->facter rename.
              (delete-file "agent/facter-ng.gemspec")
              #t))
-                  (add-after 'unpack 'embed-iproute-reference
+         (add-after 'unpack 'embed-absolute-references
+           ;; Refer to absolute executable file names to avoid propagation.
            (lambda* (#:key inputs #:allow-other-keys)
-                      (let ((iproute (assoc-ref inputs "iproute")))
-                        ;; Provide an absolute reference to the 'ip' executable
-                        ;; to avoid propagating it.
-                        (substitute* "lib/resolvers/networking_linux_resolver.rb"
-                          (("execute\\('ip")
-                           (string-append "execute('" iproute "/sbin/ip")))
-                        #t)))
+             (substitute* (find-files "lib/resolvers" "\\.rb$")
+               (("execute\\('(which |)([^ ']+)" _ _ name)
+                (string-append "execute('" (or (which name)
+                                               name))))
+             #t))
          (delete 'check)
          (add-after 'wrap 'check
            (lambda* (#:key tests? outputs #:allow-other-keys)
@@ -492,10 +492,16 @@ graphs and can export its output to different formats.")
                  (format #t "tests disabled~%"))
              #t)))))
     (inputs
-     `(("iproute" ,iproute)
-       ("ruby-hocon" ,ruby-hocon)
+     `(("ruby-hocon" ,ruby-hocon)
        ("ruby-sys-filesystem" ,ruby-sys-filesystem)
-       ("ruby-thor" ,ruby-thor)))
+       ("ruby-thor" ,ruby-thor)
+
+       ;; For ‘embed-absolute-references’.
+       ("dmidecode" ,dmidecode)
+       ("inetutils" ,inetutils)         ; for ‘hostname’
+       ("iproute" ,iproute)
+       ("pciutils" ,pciutils)
+       ("util-linux" ,util-linux)))
     (synopsis "Collect and display system facts")
     (description
      "Facter is a tool that gathers basic facts about nodes (systems) such