From 796c00fb03e50e9b8642ddf6104e1ca0794e975d Mon Sep 17 00:00:00 2001
From: Greg Gauthier <gmgauthier@protonmail.com>
Date: Sun, 3 May 2026 15:45:55 +0100
Subject: [PATCH] fix(install): add early systemd detection to prevent
 mid-install failures

- Enhance `handle_systemd()` to check for `/run/systemd/system` and exit early if systemd is not PID 1, with user-friendly error messages.
- Update README.md notes for Devuan and SYSTEMD_MODE to reflect the new behavior and clarify requirements.
---
 README.md                    |  4 ++--
 install_sdrplay_universal.sh | 10 ++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 16e0372..69f8f70 100644
--- a/README.md
+++ b/README.md
@@ -37,7 +37,7 @@ Other derivatives are detected automatically via the `ID_LIKE` field in `/etc/os
 - Debian 13
   - NOTE: The Debian project is no longer using a standard package name for `libasound2`. Not to worry, apt will automatically select the `libasound2t64` packages it needs. For all derivative distributions, therefore, the package name will remain "libasound2". 
 - Devuan 6.1 Excalibur 
-  - NOTE: the server-mode installation will not work here, because Devuan does not support systemd)
+  - NOTE: server-mode installation is unavailable here, because Devuan does not use systemd. The installer detects this and refuses `SYSTEMD_MODE=install` up front rather than failing mid-install.
 - Manjaro
 - Fedora 44
 - OpenMandriva 6
@@ -60,7 +60,7 @@ The script will present the SDRPlay license agreement and prompt for acceptance
 - `ACCEPTLICENSE=1` — Skip the interactive license prompt
 - `DONOTDOWNLOAD=1` — Use local tarballs instead of downloading (place them in the current directory). Also skips the upstream lookup (build hashes and licence text); pin filenames with the override variables below
 - `NOTSUPPORTED=1` — Skip dependency checks entirely (install them yourself)
-- `SYSTEMD_MODE=install SYSTEMD_TARGET=sdrconnectserver` — Enable the server systemd service
+- `SYSTEMD_MODE=install SYSTEMD_TARGET=sdrconnectserver` — Enable the server systemd service (requires systemd as PID 1; refuses to run otherwise)
 - `SDRCONNECT_GITBUILD=<hash>` — Pin the SDRconnect build hash, bypassing the upstream lookup
 - `RIGCONTROL_GITBUILD=<hash>` — Pin the RigControl build hash, bypassing the upstream lookup
 
diff --git a/install_sdrplay_universal.sh b/install_sdrplay_universal.sh
index a9f22a3..30af5a1 100755
--- a/install_sdrplay_universal.sh
+++ b/install_sdrplay_universal.sh
@@ -584,6 +584,16 @@ handle_systemd() {
         return
     fi
 
+    # systemd creates /run/systemd/system when it is PID 1. Bail out early on
+    # non-systemd inits (Devuan, Artix-openrc/runit, Slackware, etc.) so we
+    # don't fail mid-install and trigger the rollback trap.
+    if [[ ! -d /run/systemd/system ]]; then
+        error "SYSTEMD_MODE=$mode requested, but systemd is not the active init on this system."
+        error "Re-run without SYSTEMD_MODE (or with SYSTEMD_MODE=skip) and configure the"
+        error "service manually using your distro's init system (sysvinit, openrc, runit, ...)."
+        exit 1
+    fi
+
     # Only resolve target if we actually need it
     local target="${SYSTEMD_TARGET:-}"