(address . guix-patches@gnu.org)
20210721014047.3878a0c7@tachikoma.lepiller.eu
Hi Guix!
This patch improves error reporting a bit when making mistakes in guix
records. This is motivated by a user getting "invalid field specifier"
for their whole services field in their os record. With this patches,
they would have seen:
multiple values in field specifier. Got 2 values associated with key
services. Values are:
(append (list (service ...) ...))
(modify-services %desktop-services ...)
Which would have hinted them at fixing the parenthesis. Or at least, it
would have saved us some time trying to count them :)
Here are the cases that are handled and the associated message:
(operating-system
services)
guix system: error: services: invalid field specifier. The format of a
field is `(services value)'
(operating-system
(services))
test.scm:2:2: error: (services): Value missing in field specifier. The
format of a field is `(services value)'.
(operating-system
(services 1 2 3))
test.scm:2:2: error: (services 1 2 3): multiple values in field
specifier. Got 3 values associated with key services. Values are:
1
2
3
(operating-system
())
guix system: error: (): invalid field specifier. The format of a field
is `(field value)'
(operating-system
((services %desktop-services)))
test.scm:2:2: error: ((services %desktop-services)): invalid field
specifier. (services %desktop-services) is not a valid field name.
Of course, we can improve these error messages, and internationalize
them.
WDYT?
From 4cde5555682ca6a3c78cb274cc308087e51ea0e9 Mon Sep 17 00:00:00 2001
From: Julien Lepiller <julien@lepiller.eu>
Date: Wed, 21 Jul 2021 01:30:04 +0200
Subject: [PATCH] guix: records: Improve error reporting.
* guix/records.scm (report-invalid-field-specifier): Handle various
invalidity causes separately.
---
guix/records.scm | 37 ++++++++++++++++++++++++++++++++++---
1 file changed, 34 insertions(+), 3 deletions(-)
Toggle diff (58 lines)
diff --git a/guix/records.scm b/guix/records.scm
index 3d54a51956..3c3dd478a5 100644
--- a/guix/records.scm
+++ b/guix/records.scm
@@ -1,6 +1,7 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2018 Mark H Weaver <mhw@netris.org>
+;;; Copyright © 2021 Julien Lepiller <julien@lepiller.eu>
;;;
;;; This file is part of GNU Guix.
;;;
@@ -83,10 +84,40 @@ error-reporting purposes."
;; WEIRD may be an identifier, thus lacking source location info, and
;; BINDINGS is a list, also lacking source location info. Hopefully
;; PARENT-FORM provides source location info.
- (apply syntax-violation name "invalid field specifier"
- (if parent-form
+ (syntax-case #'weird ()
+ (() ;the empty list
+ (apply syntax-violation name
+ "invalid field specifier. The format of a field is `(field value)'"
(list parent-form #'weird)
- (list #'weird)))))))
+ (list #'weird)))
+ (((field ...) _ ...) ;a list whose first element is a list
+ (apply syntax-violation name
+ (format #f "invalid field specifier. ~a is not a valid field name."
+ (map syntax->datum #'(field ...)))
+ (list parent-form #'weird)
+ (list #'weird)))
+ ((field) ;a list with one element
+ (apply syntax-violation name
+ (format #f "Value missing in field specifier. The format of \
+a field is `(~a value)'."
+ (syntax->datum #'field))
+ (list parent-form #'weird)
+ (list #'weird)))
+ ((field value ...) ;any other list
+ (apply syntax-violation name
+ (format #f "multiple values in field specifier. Got ~a values \
+associated with key ~a. Values are:~%~{~a~%~}"
+ (length #'(value ...)) (syntax->datum #'field)
+ (map syntax->datum #'(value ...)))
+ (list parent-form #'weird)
+ (list #'weird)))
+ (field ;not a list
+ (apply syntax-violation name
+ (format #f "invalid field specifier. The format of a field \
+is `(~a value)'"
+ (syntax->datum #'field))
+ (list parent-form #'weird)
+ (list #'weird))))))))
(define (report-duplicate-field-specifier name ctor)
"Report the first duplicate identifier among the bindings in CTOR."
--
2.32.0