evaluate: Use a generic key to identify Cuirass arguments.

So that Cuirass specifications used to build 'guix-modular' can be named
differently than "guix" and "guix-modular" (see Guix's
build-aux/hydra/guix-modular.scm).

The name is used as a primary key, so before that commit, it was also
impossible to have several such specifications.

This is a workaround, Cuirass should normally support several inputs per
specification, as Hydra does.  The specification's name would then only be
used to identify it.  See <https://bugs.gnu.org/31813

>.

* bin/evaluate.in (main): Replace custom NAME (passed to PROC) with 'guix'.

Co-authored-by: Mathieu Othacehe <m.othacehe@gmail.com>

bin/evaluate.in

@@ -6,7 +6,8 @@ exec ${GUILE:-@GUILE@} --no-auto-compile -e main -s "$0" "$@"
 ;;;; evaluate -- convert a specification to a job list
 ;;; Copyright © 2016, 2018 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2016, 2017 Mathieu Lirzin <mthl@gnu.org>
-;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
+;;; Copyright © 2017, 2018 Mathieu Othacehe <m.othacehe@gmail.com>
+;;; Copyright © 2018 Clément Lassieur <clement@lassieur.org>
 ;;;
 ;;; This file is part of Cuirass.
 ;;;
@@ -98,7 +99,7 @@ building things during evaluation~%")
                 (proc    (module-ref %user-module proc-name))
                 (commit  (assq-ref spec #:current-commit))
                 (name    (assq-ref spec #:name))
-                (args    `((,(string->symbol name)
+                (args    `((guix
                             (revision . ,commit)
                             (file-name . ,source))
                            ,@(or (assq-ref spec #:arguments) '())))