commit ecdaaf222a126ec9aeecb0479e2337f875a9618f
Author: Alexey Serbin <alexey@apache.org>
Date:   Tue Aug 20 16:47:02 2019 -0700

    main: allow to run under regular user in server-only mode
    
    This patch allows for running chronyd under non-superuser account when
    no clock control is requested (i.e. when '-d' option is specified).
    
    The motivation for this change is to run chronyd in server-only mode
    (i.e. not driving system's clock) in various development and testing
    environments.  Of course, it's assumed non-standard ports are used
    for the NTP and the command endpoints in such a case, otherwise
    chronyd would fail to bind to the standard NTP (123) and
    command (323) ports since these are privileged ones.

diff --git a/main.c b/main.c
index fafca65..d94a3b5 100644
--- a/main.c
+++ b/main.c
@@ -501,8 +501,9 @@ int main
     }
   }
 
-  if (getuid() && !client_only)
+  if (getuid() && !(client_only || !clock_control)) {
     LOG_FATAL("Not superuser");
+  }
 
   /* Turn into a daemon */
   if (!nofork) {