diff --git a/src/app/launcher.php b/src/app/launcher.php
index 87834d4..81b0b93 100644
--- a/src/app/launcher.php
+++ b/src/app/launcher.php
@@ -23,7 +23,7 @@ class launcher {
       "--internal-use", $tmpfile->getFile(),
       $appClass, "--", ...$args,
     ]);
-    $cmd->addRedir("null");
+    $cmd->addRedir("both", "/tmp/_nulib_launch-launcher.log");
     $cmd->passthru($exitcode);
 
     # attendre un peu que la commande aie le temps de s'initialiser
@@ -51,8 +51,9 @@ class launcher {
       try {
         # puis lancer la commande
         $cmd = new Cmd($args);
-        #XXX fichier de log?
         $cmd->addSource("/g/init.env");
+        $cmd->addRedir("both", "/tmp/_nulib_launch-app.log");
+        #XXX prendre le fichier de log de $runfile si possible?
         $cmd->addRedir("null");
         msg::debug("$pid: launching\n".$cmd->getCmd());
         $cmd->fork_exec($exitcode);