[bug#71697] [PATCH v4 1/2] scripts: lint: Add 'dry-run' option.

[Simon Tournier]

* guix/scripts/lint.scm (guix-lint)[show-package-checkers]: New procedure.
(show-help, %options): Add 'dry-run' option.
* doc/guix.texi: Document it.

Change-Id: I8c96e376d52c0961ccf2ab39f1fc856c762b089d
---
 doc/guix.texi         |  3 +++
 guix/scripts/lint.scm | 26 ++++++++++++++++++++++----
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 5b77c84b4a..6043962038 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -15463,6 +15463,9 @@ Invoking guix lint
 List and describe all the available checkers that will be run on packages
 and exit.
 
+@item --dry-run
+Do not run the checkers.
+
 @item --checkers
 @itemx -c
 Only enable the checkers specified in a comma-separated list using the
diff --git a/guix/scripts/lint.scm b/guix/scripts/lint.scm
index ee3de51fb1..1b13d6e17f 100644
--- a/guix/scripts/lint.scm
+++ b/guix/scripts/lint.scm
@@ -100,6 +100,8 @@ (define (show-help)
   (display (G_ "Usage: guix lint [OPTION]... [PACKAGE]...
 Run a set of checkers on the specified package; if none is specified,
 run the checkers on all packages.\n"))
+  (display (G_ "
+      --dry-run          do not run checkers "))
   (display (G_ "
   -c, --checkers=CHECKER1,CHECKER2...
                          only run the specified checkers"))
@@ -154,6 +156,9 @@ (define %options
         (option '(#\n "no-network") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'no-network? #t result)))
+        (option '("dry-run") #f #f
+                (lambda (opt name arg result)
+                  (alist-cons 'dry-run? #t result)))
         (find (lambda (option)
                 (member "load-path" (option-names option)))
               %standard-build-options)
@@ -218,14 +223,27 @@ (define-command (guix-lint . args)
                 (proc store))
               (proc #f)))
 
+        (define (show-package-checkers package checkers)
+          (format (current-error-port) "~a@~a checked by~{ ~a~}.~%"
+                  (package-name package)
+                  (package-version package)
+                  (sort (map (compose symbol->string lint-checker-name)
+                             checkers)
+                   string<?)))
+
         (call-maybe-with-store
          (lambda (store)
            (cond
             ((null? args)
-             (fold-packages (lambda (p r) (run-checkers p checkers
-                                                        #:store store)) '()))
+             (fold-packages (lambda (p r)
+                              (show-package-checkers p checkers)
+                              (when (not (assoc-ref opts 'dry-run?))
+                                (run-checkers p checkers
+                                              #:store store))) '()))
             (else
              (for-each (lambda (package)
-                         (run-checkers package checkers
-                                       #:store store))
+                         (show-package-checkers package checkers)
+                         (when (not (assoc-ref opts 'dry-run?))
+                             (run-checkers package checkers
+                                           #:store store)))
                        args)))))))))

base-commit: 2d6a3799fcda5c017f653c6e96b91964b07a7ee0
-- 
2.41.0