From 4d59596a1c5f6b20870e619cbf67068ac7dd64ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Sun, 7 Nov 2021 15:56:19 +0100
Subject: [PATCH] ui: 'load*' correctly reports 'read-error' in all cases.

Previously, 'read-error' exceptions other than "missing closing paren"
would not be reported; instead, we'd directly call (exit 1) without
printing anything.

Fixes <https://issues.guix.gnu.org/51463>.
Reported by Alice BRENON <alice.brenon@ens-lyon.fr>.

* guix/ui.scm (report-load-error): Report the error without re-throwing
upon 'read-error'.
* tests/guix-build.sh: Add test.
---
 guix/ui.scm         |  3 ++-
 tests/guix-build.sh | 12 +++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/guix/ui.scm b/guix/ui.scm
index b01bb3d587..bd999103ff 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -377,7 +377,8 @@ ARGS is the list of arguments received by the 'throw' handler."
                                       (+ 2 (string-contains message ": ")))))
            (format (current-error-port) (G_ "~amissing closing parenthesis~%")
                    location))
-         (apply throw args)))
+         (report-error (G_ "read error while loading '~a': ~a~%")
+                       file (apply format #f message args))))
     (('syntax-error proc message properties form subform . rest)
      (let ((loc (source-properties->location properties)))
        (report-error loc (G_ "~s: ~a~%")
diff --git a/tests/guix-build.sh b/tests/guix-build.sh
index e20702c521..46c8afc901 100644
--- a/tests/guix-build.sh
+++ b/tests/guix-build.sh
@@ -1,5 +1,5 @@
 # GNU Guix --- Functional package management for GNU
-# Copyright © 2012, 2013, 2014, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+# Copyright © 2012, 2013, 2014, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 # Copyright © 2020 Marius Bakke <mbakke@fastmail.com>
 # Copyright © 2021 Chris Marusich <cmmarusich@gmail.com>
 #
@@ -77,6 +77,16 @@ module_dir="t-guix-build-$$"
 mkdir "$module_dir"
 trap "rm -rf $module_dir" EXIT
 
+# Check error reporting for '-f'.
+cat > "$module_dir/foo.scm" <<EOF
+(use-modules (guix))
+) ;extra closing paren
+EOF
+! guix build -f "$module_dir/foo.scm" 2> "$module_dir/stderr"
+grep "read error" "$module_dir/stderr"
+rm "$module_dir/stderr" "$module_dir/foo.scm"
+
+# Check 'GUIX_PACKAGE_PATH' & co.
 cat > "$module_dir/foo.scm"<<EOF
 (define-module (foo)
   #:use-module (guix tests)