diff --git a/bin/miaou-bash b/bin/miaou-bash
index 45dd88b..6b7b4c9 100755
--- a/bin/miaou-bash
+++ b/bin/miaou-bash
@@ -287,6 +287,20 @@ function dump_failure {
   miaou_debug '</error_box>'
 }
 
+function save_err_trace_to_main {
+  miaou_debug "<save_stacktrace_to_stderr count=${#error_source[@]} to=${MIAOU_BASH_ERROR_CHILDREN}>"
+  local i source lineno funcname
+  for i in "${!error_source[@]}"; do
+    source="${error_source[$i]}"
+    lineno="${error_lineno[$i]}"
+    funcname="${error_funcname[$i]}"
+    miaou_debug "<trace source=${source} lineno=${lineno} funcname=${funcname}/>"
+    >>"$MIAOU_BASH_ERROR_CHILDREN" echo "miaou_trace: source=${source} lineno=${lineno} funcname=${funcname}"
+  done
+  for i in "${tmp_error[@]}"; do >>"$MIAOU_BASH_ERROR_CHILDREN" echo "$i"; done
+  miaou_debug "</save_stacktrace_to_stderr>"
+}
+
 function dump_stacktrace {
   miaou_debug "<stacktrace count=${#error_source[@]}>"
   local i source lineno funcname
@@ -354,12 +368,12 @@ function on_exit {
   elif [[ -v failure_type && "$failure_type" == 'COMMAND_NOT_FOUND' ]]; then
     unset 'tmp_error[-1]' 'tmp_error[-1]'
     add_miaou_error "${BASH_SOURCE[2]}" "${BASH_LINENO[1]}" "${failure_code}" "${failure_type}" "${failure_payload}"
-    miaou_debug '<command_not_found change_stderr />'
+    miaou_debug "<command_not_found change_stderr count=${#tmp_error[@]}/>"
 
   elif [[ -v failure_type && "$failure_type" == 'FILE_NOT_FOUND' ]]; then
     unset 'tmp_error[-1]' 'tmp_error[-1]'
     add_miaou_error "${BASH_SOURCE[2]}" "${BASH_LINENO[1]}" "${failure_code}" "${failure_type}" "${failure_payload}"
-    miaou_debug '<file_not_found change_stderr />'
+    miaou_debug "<file_not_found change_stderr count=${#tmp_error[@]}/>"
 
   elif [[ ! -v failure_type ]]; then
     if [[ $failure_code -gt 0 && ${#tmp_error[@]} -gt 0 ]]; then
@@ -406,13 +420,18 @@ function on_exit {
     fi
   fi
 
-  2>&3 >&3 dump_stderr
-  if [[ -v failure_type ]]; then
-    2>&3 >&4 dump_failure
-    if [[ -v error_source ]]; then
-      2>&3 >&4 dump_stacktrace
+  if ! is_true $CHILD_PROCESS; then
+    2>&3 >&3 dump_stderr
+    if [[ -v failure_type ]]; then
+      2>&3 >&4 dump_failure
+      if [[ -v error_source ]]; then
+        2>&3 >&4 dump_stacktrace
+      fi
     fi
+  elif [[ -v failure_type ]]; then
+    2>&3 >&4 save_err_trace_to_main
   fi
+
   if [[ $failure_code -gt 0 ]]; then
     miaou_debug "</on_exit code=$failure_code>"
   else
@@ -431,6 +450,7 @@ function build_miaou_bash_error {
   mkdir -p "$directory"
   if is_true $CHILD_PROCESS; then
     MIAOU_BASH_ERROR="${directory}/${PPID}.$$.tmp"
+    MIAOU_BASH_ERROR_CHILDREN="${directory}/${PPID}.children.tmp"
   else
     MIAOU_BASH_ERROR="${directory}/$$.tmp"
   fi
@@ -440,9 +460,11 @@ function build_miaou_bash_error {
 }
 
 function cleanup {
-  miaou_debug '<cleanup/>'
-  # trap - ERR EXIT PIPE RETURN
-  # rm "$MIAOU_BASH_ERROR"
+  if ! is_true $CHILD_PROCESS; then
+    miaou_debug '<cleanup main/>'
+    trap - ERR EXIT PIPE RETURN
+    # rm "$MIAOU_BASH_ERROR"
+  fi
 }
 
 ## main
@@ -459,8 +481,14 @@ trap 'on_exit $?' EXIT
 trap 'on_pipe' PIPE
 trap 'on_return' RETURN
 
-if [[ -e /proc/$$/fd/3 ]]; then exec 4>&3 3>&-; else exec 4>/dev/tty; fi # swap fd 3 4 when fd 3 sent off
-exec 3>/dev/stderr 2>"$MIAOU_BASH_ERROR"
+if ! is_true "$CHILD_PROCESS"; then
+  # main
+  [[ -e /proc/$$/fd/3 ]] && exec 4>&3 3>&- || exec 4>/dev/tty # swap fd 3 4 when fd 3 sent off
+  exec 3>/dev/stderr 2>"$MIAOU_BASH_ERROR"
+else
+  # any children
+  exec 4>/dev/tty 2>"$MIAOU_BASH_ERROR"
+fi
 
 if is_true "$CHILD_PROCESS"; then
   miaou_debug "<child file=$BASH_ARGV0 pid=${BASHPID} parent=${PPID}>"
diff --git a/test/stub/extra/library.bash b/test/stub/extra/library.bash
index 3f996ec..daa2191 100755
--- a/test/stub/extra/library.bash
+++ b/test/stub/extra/library.bash
@@ -1,22 +1,12 @@
 #!/usr/bin/env miaou-bash
 #!/usr/bin/env bash
 
-function blabla {
-  echo IN blabla OUT
-  >&2 echo stderr from utility
-  # . lib/not_found_again.bash
-  # lib/not_found_again.bash
-  suite
-}
+BASEDIR=$(dirname "$0")
 
-function suite {
-  command_not_found
-  grep nope nope
-  exit
-  exit 10 # youpi
-  echo $nope
-  return 7
-  return
+function library {
+  echo library loaded
+  >&2 echo stderr from library
+  "$BASEDIR/onemore.bash"
 }
 
-blabla
+library
diff --git a/test/stub/scenario.bash b/test/stub/scenario.bash
index 73953f6..946000f 100755
--- a/test/stub/scenario.bash
+++ b/test/stub/scenario.bash
@@ -92,8 +92,9 @@ function do_file_not_found {
 
 function do_child_error {
   "$BASEDIR/extra/library.bash"
+  # . "$BASEDIR/extra/library.bash"
+
   echo SHOULD NOT APPEAR
-  . "$BASEDIR/extra/library.bash"
 }
 
 function do_command_error {