[bug#66793] [PATCH 1/3] tests: Make ‘guix time-machine’ test effective.

["Ludovic Courtès" <ludo@gnu.org>]

The test as added in 79ec651a286c71a3d4c72be33a1f80e76a560031 had no
effect: first because ‘guix time-machine --commit=X’, not followed by a
command, does nothing, and second because the “! COMMAND” shell stanza
does not have the desired effect (see <https://issues.guix.gnu.org/62406>).

This change rewrites the test to make it effective.

* tests/guix-time-machine.sh: Rewrite.

Change-Id: Ib44a11331c8625e346139a236cffa699cdbd02f2
---
 tests/guix-time-machine.sh | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/tests/guix-time-machine.sh b/tests/guix-time-machine.sh
index 8b62ef75ea..a78c1533fb 100644
--- a/tests/guix-time-machine.sh
+++ b/tests/guix-time-machine.sh
@@ -1,5 +1,6 @@
 # GNU Guix --- Functional package management for GNU
 # Copyright © 2023 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+# Copyright © 2023 Ludovic Courtès <ludo@gnu.org>
 #
 # This file is part of GNU Guix.
 #
@@ -20,9 +21,24 @@
 # Test the 'guix time-machine' command-line utility.
 #
 
-guix time-machine --version
+if [ -d "$abs_top_srcdir/.git" ] \
+   || guile -c '(getaddrinfo "www.gnu.org" "80" AI_NUMERICSERV)' 2> /dev/null
+then
+    guix time-machine --version
+else
+    echo "This test requires networking or a local Git checkout; skipping." >&2
+    exit 77
+fi
 
-# Visiting a commit older than v1.0.0 fails.
-! guix time-machine --commit=v0.15.0
+if [ -d "$abs_top_srcdir/.git" ]
+then
+    EXTRA_OPTIONS="--url=$abs_top_srcdir"
+else
+    EXTRA_OPTIONS=""
+fi
 
-exit 0
+# Visiting a commit older than v1.0.0 must fail (this test is expensive
+# because it clones the whole repository).
+guix time-machine -q --commit=v0.15.0 $EXTRA_OPTIONS -- describe && false
+
+true
-- 
2.41.0