fix unbound_variable

poc

@@ -74,7 +74,7 @@ function on_return {
     failure_type="RETURN"
     failure_payload="${FUNCNAME[0]}"
     print_miaou_error "${BASH_SOURCE[1]}" "${BASH_LINENO[0]}" "${failure_code}" "${failure_type}" "${failure_payload}"
-    miaou_debug "<on_return code=$failure_code payload=$failure_payload />"
+    miaou_debug "<on_return code=$failure_code payload=$failure_payload/>"
   fi
   true
 }
@@ -95,7 +95,7 @@ function exit {
   failure_type="EXIT"
   failure_payload="${error_funcname[0]}"
 
-  miaou_debug "<exit code=$failure_code overridden />"
+  miaou_debug "<exit code=$failure_code overridden/>"
   print_miaou_error "${BASH_SOURCE[1]}" "${BASH_LINENO[0]}" "${failure_code}" "${failure_type}" "${failure_payload}"
   builtin exit "$failure_code"
 }
@@ -147,9 +147,9 @@ function on_error {
     error_funcname=("${error_funcname[@]}")
 
     if [[ -v failure_payload ]]; then
-      miaou_debug "</on_error exit=$failure_code type=${failure_type} payload={${failure_payload}} >"
+      miaou_debug "</on_error exit=$failure_code type=${failure_type} payload={${failure_payload}}>"
     else
-      miaou_debug "</on_error exit=$failure_code type=${failure_type} >"
+      miaou_debug "</on_error exit=$failure_code type=${failure_type}>"
     fi
 
     builtin exit "$failure_code"
@@ -163,6 +163,7 @@ function on_error {
 function on_pipe {
   trap - RETURN
   local tmp_error regex source lineno
+  miaou_debug "<on_pipe sub_pid=$BASHPID pid=$$>"
 
   error_source=("${BASH_SOURCE[@]}")
   error_lineno=("${BASH_LINENO[@]}")
@@ -171,7 +172,8 @@ function on_pipe {
   unset 'error_source[-1]' 'error_lineno[-1]' 'error_funcname[-1]'
   unset 'error_source[-1]' 'error_lineno[-1]' 'error_funcname[-1]'
 
-  mapfile -t tmp_error <"$MIAOU_BASH_ERROR"
+  miaou_debug '<load_tmp_error/>' && mapfile -t tmp_error <"$MIAOU_BASH_ERROR"
+
   last_error="${tmp_error[-1]}"
   regex='^(.*): line ([0-9]+): miaou_error: SUBSHELL_ERROR ([0-9]+) payload: (.*)$'
   if [[ $last_error =~ $regex ]]; then
@@ -187,7 +189,7 @@ function on_pipe {
     failure_code=141
     failure_type="PIPE_ERROR"
   fi
-  miaou_debug "<on_pipe code=$failure_code sub_pid=$BASHPID pid=$$ />"
+  miaou_debug "</on_pipe/>"
   builtin exit "$failure_code"
 }
 
@@ -225,7 +227,7 @@ function dump_failure {
 }
 
 function dump_stacktrace {
-  miaou_debug "<stacktrace count=${#error_source[@]} >"
+  miaou_debug "<stacktrace count=${#error_source[@]}>"
   local i source lineno funcname
   for i in "${!error_source[@]}"; do
     tty_ansi FG_MAGENTA
@@ -247,15 +249,17 @@ function on_exit {
   trap - RETURN
   local code="${1:-0}" last_error regex
 
-  miaou_debug "<on_exit code=$code >"
+  miaou_debug "<on_exit code=$code>"
 
-  [[ ! -v tmp_error ]] && mapfile -t tmp_error <"$MIAOU_BASH_ERROR"
+  [[ ! -v tmp_error ]] &&
+    miaou_debug '<load_tmp_error/>' &&
+    mapfile -t tmp_error <"$MIAOU_BASH_ERROR"
 
   if [[ -v failure_type && "$failure_type" == 'RETURN' ]]; then
     last_error="${tmp_error[-1]}"
     regex='^(.*): line ([0-9]+): miaou_error: RETURN [0-9]+'
     if [[ "$last_error" =~ $regex ]]; then
-      miaou_debug "<return code=$code />"
+      miaou_debug "<return code=$code/>"
       local source line
       source="${BASH_REMATCH[1]}"
       line="${BASH_REMATCH[2]}"
@@ -263,24 +267,21 @@ function on_exit {
       error_lineno=("$line" "${error_lineno[@]}")
       error_funcname=("$failure_payload" "${error_funcname[@]}")
     else
-      miaou_debug "<return type=unexpected />"
+      miaou_debug "<return type=unexpected/>"
     fi
 
   else
     if [[ $code -gt 0 && ${#tmp_error[@]} -gt 0 ]]; then
       last_error="${tmp_error[-1]}"
-      miaou_debug "<on_exit_tmp_error last={$last_error} >"
+      miaou_debug "<on_exit_tmp_error last={$last_error}>"
       if [[ $code -eq 1 ]]; then
         regex='^(.*): line ([0-9]+): (.*): unbound variable$'
         if [[ "$last_error" =~ $regex ]]; then
           local source line payload
+
           source="${BASH_REMATCH[1]}"
           line="${BASH_REMATCH[2]}"
           payload="${BASH_REMATCH[3]}"
-          miaou_debug "<unbound_variable source=${source} line=${line} payload={${payload}} >"
-          failure_code=$code
-          failure_type='UNBOUND_VARIABLE'
-          failure_payload="${BASH_REMATCH[3]}"
           error_source=("${BASH_SOURCE[@]}")
           error_lineno=("${BASH_LINENO[@]}")
           error_funcname=("${FUNCNAME[@]}")
@@ -290,6 +291,11 @@ function on_exit {
           error_source=("$source" "${error_source[@]}")
           error_lineno=("$line" "${error_lineno[@]}")
           error_funcname=("${error_funcname[@]}" '<main>')
+
+          failure_code=$code
+          failure_type='UNBOUND_VARIABLE'
+          failure_payload=$payload
+          miaou_debug "<unbound_variable source=${source} line=${line} payload={${failure_payload}}>"
         fi
       fi
       miaou_debug "</on_exit_tmp_error>"
@@ -302,9 +308,9 @@ function on_exit {
     2>&3 >&4 dump_stacktrace
   fi
   if [[ $code -gt 0 ]]; then
-    miaou_debug "</on_exit exit=$code >"
+    miaou_debug "</on_exit exit=$code>"
   else
-    miaou_debug "</on_exit success >"
+    miaou_debug "</on_exit success>"
   fi
 }
 
@@ -325,6 +331,6 @@ 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"
 
-miaou_debug "<source from=$BASH_ARGV0 pid=${BASHPID} />"
+miaou_debug "<source from=$BASH_ARGV0 pid=${BASHPID}/>"
 # shellcheck source=/dev/null
 source "$BASH_ARGV0"