[bug#74258] [PATCH 3/3] guix-install.sh: Run the uninstall even if already partially done

[David Boilleau via Guix-patches via <guix-patches@gnu.org>]

Removing users, groups or Systemd units fails if they are already absent,
causing the uninstall script to exit. The goal here is to make the uninstall
always run entirely, whatever parts are already done.

* etc/guix-install.sh (sys_delete_build_user): Test if users and groups exist
before deleting them.
(sys_delete_guix_daemon): Test if /etc/systemd/system/guix-daemon.service file
exists before removing the matching Systemd unit.

Change-Id: Ibffb1f1b39de675542fb8057af21ecaea1b53d4c
---
 etc/guix-install.sh | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/etc/guix-install.sh b/etc/guix-install.sh
index 7fb5ac63c5..f07b2741bb 100755
--- a/etc/guix-install.sh
+++ b/etc/guix-install.sh
@@ -451,11 +451,15 @@ sys_create_build_user()
 sys_delete_build_user()
 {
     for i in $(seq -w 1 10); do
-        userdel -f guixbuilder${i}
+        if id -u "guixbuilder${i}" &>/dev/null; then
+            userdel -f guixbuilder${i}
+        fi
     done

     _msg "${INF}delete group guixbuild"
-    groupdel -f guixbuild
+    if getent group guixbuild &>/dev/null; then
+        groupdel -f guixbuild
+    fi
 }

 sys_enable_guix_daemon()
@@ -569,12 +573,14 @@ sys_delete_guix_daemon()
             ;;

         systemd)
-            _msg "${INF}disabling guix-daemon"
-            systemctl disable guix-daemon
-            _msg "${INF}stopping guix-daemon"
-            systemctl stop guix-daemon
-            _msg "${INF}removing guix-daemon"
-            rm -f /etc/systemd/system/guix-daemon.service
+            if [ -f /etc/systemd/system/guix-daemon.service ]; then
+                _msg "${INF}disabling guix-daemon"
+                systemctl disable guix-daemon
+                _msg "${INF}stopping guix-daemon"
+                systemctl stop guix-daemon
+                _msg "${INF}removing guix-daemon"
+                rm -f /etc/systemd/system/guix-daemon.service
+            fi

             if [ -f /etc/systemd/system/gnu-store.mount ]; then
                 _msg "${INF}disabling gnu-store.mount"
--
2.43.0