Index: src/daemon/overseer/PhutilDaemonOverseer.php
===================================================================
--- src/daemon/overseer/PhutilDaemonOverseer.php
+++ src/daemon/overseer/PhutilDaemonOverseer.php
@@ -40,6 +40,7 @@
   private $traceMemory;
   private $daemonize;
   private $phddir;
+  private $conduit;
   private $conduitURI;
 
   public function __construct($daemon, array $argv) {
@@ -135,9 +136,18 @@
 
     $exec_dir = $root.'/scripts/daemon/exec/';
 
+    // NOTE: In Ubuntu, this command is executed via an intermediary shell
+    // due to some awkward implemenation artifact beyond our control.
+    // We use 'exec' to replace it with the real process; without this,
+    // the child will call posix_getppid(), be given the pid of the 'sh -c'
+    // process, and send it SIGUSR1 to keepalive which will terminate it
+    // immediately. We also won't be able to do process group management
+    // because the shell process won't properly posix_setsid() so the pgid
+    // of the child won't be meaningful.
+
     $exec_daemon = './exec_daemon.php';
     $argv = $this->argv;
-    array_unshift($argv, $exec_daemon, $this->daemon);
+    array_unshift($argv, 'exec', $exec_daemon, $this->daemon);
     foreach ($argv as $k => $arg) {
       $argv[$k] = escapeshellarg($arg);
     }