Distriction specific patch, not going upstream

Disable systemd-run if the command is not found.

diff --git a/xpra/scripts/main.py b/xpra/scripts/main.py
index 1c5e8ddaad..084aabe792 100755
--- a/xpra/scripts/main.py
+++ b/xpra/scripts/main.py
@@ -396,23 +396,26 @@ def use_systemd_run(s) -> bool:
     cmd = ["systemd-run", "--quiet"]
     if getuid() != 0:
         cmd += ["--user"]
-    cmd += ["--scope", "--", "true"]
-    proc = Popen(cmd, stdout=PIPE, stderr=PIPE, shell=False)
     try:
-        proc.communicate(timeout=2)
-        r = proc.returncode
-    except TimeoutExpired:  # pragma: no cover
-        r = None
-    if r is None:
-        try:
-            proc.terminate()
-        except Exception:
-            pass
+        cmd = ["systemd-run", "--quiet", "--user", "--scope", "--", "true"]
+        proc = Popen(cmd, stdout=PIPE, stderr=PIPE, shell=False)
         try:
-            proc.communicate(timeout=1)
+            proc.communicate(timeout=2)
+            r = proc.returncode
         except TimeoutExpired:  # pragma: no cover
             r = None
-    return r == 0
+        if r is None:
+            try:
+                proc.terminate()
+            except Exception:
+                pass
+            try:
+                proc.communicate(timeout=1)
+            except TimeoutExpired:  # pragma: no cover
+                r = None
+        return r==0
+    except FileNotFoundError:
+        return False


 def verify_gir():
achefilesd.scm?id=0b95de9b3bad19da20cb034ca2bc245c2b48cf00'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/tests/cachefilesd.scm'>
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<option value='grep'>log msg</option>
<option value='author'>author</option>
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<div class='path'>path: <a href='/guix/log/?id=0b95de9b3bad19da20cb034ca2bc245c2b48cf00'>root</a>/<a href='/guix/log/gnu?id=0b95de9b3bad19da20cb034ca2bc245c2b48cf00'>gnu</a>/<a href='/guix/log/gnu/tests?id=0b95de9b3bad19da20cb034ca2bc245c2b48cf00'>tests</a>/<a href='/guix/log/gnu/tests/cachefilesd.scm?id=0b95de9b3bad19da20cb034ca2bc245c2b48cf00'>cachefilesd.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/tests/cachefilesd.scm?id=0b95de9b3bad19da20cb034ca2bc245c2b48cf00&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-08-15 23:30:44 +0200'>2023-08-15</span></td><td><a href='/guix/commit/gnu/tests/cachefilesd.scm?id=b8ee6b8a59bf02f47a6668e016905308b441523e'>services: Add cachefilesd service.</a><span class='msg-avail'>...<span class='msg-tooltip'>Thanks to Bruno Victal "mirai" for cooperating on this patch and for
generously sharing a wealth of insights about Guix services.

Thanks to Jean-Baptiste Note for an early version of this service!

* doc/guix.texi (Linux Services)[Cachefilesd Service]: New heading.
* gnu/services/linux.scm (serialize-string, non-negative-integer?)
(serialize-non-negative-integer, string, non-negative-integer)
(make-option-serializer, make-percentage-threshold-serializer): New
procedures.
(cachefilesd-configuration): New record type.
(cachefilesd-service-type): New variable.
* gnu/tests/cachefilesd.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

Co-authored-by: Bruno Victal &lt;mirai@makinata.eu&gt;
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Felix Lechner</td></tr>