From 6770481c639e9f0953619b52ca127fe5bbaeec71 Mon Sep 17 00:00:00 2001
From: Mike Macgirvin <mikemacgirvin@catalyst-au.net>
Date: Wed, 23 Mar 2022 10:52:14 +1100
Subject: [PATCH] MDL-70568 cron: Temporarily increase debug level on task
 failure

---
 lib/cronlib.php | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/lib/cronlib.php b/lib/cronlib.php
index 0cf405b210f..0ec7f06e772 100644
--- a/lib/cronlib.php
+++ b/lib/cronlib.php
@@ -236,6 +236,7 @@ function cron_run_adhoc_tasks(int $timenow, $keepalive = 0, $checklimits = true)
  */
 function cron_run_inner_scheduled_task(\core\task\task_base $task) {
     global $CFG, $DB;
+    $debuglevel = $CFG->debug;
 
     \core\task\manager::scheduled_task_starting($task);
     \core\task\logmanager::start_logging($task);
@@ -250,6 +251,11 @@ function cron_run_inner_scheduled_task(\core\task\task_base $task) {
     try {
         get_mailer('buffer');
         cron_prepare_core_renderer();
+        // Temporarily increase debug level if task has failed and debugging isn't already at maximum.
+        if ($debuglevel !== DEBUG_DEVELOPER && $faildelay = $task->get_fail_delay()) {
+            mtrace('Debugging increased temporarily due to faildelay of ' . $faildelay);
+            set_debugging(DEBUG_DEVELOPER);
+        }
         $task->execute();
         if ($DB->is_transaction_started()) {
             throw new coding_exception("Task left transaction open");
@@ -280,6 +286,10 @@ function cron_run_inner_scheduled_task(\core\task\task_base $task) {
         }
         \core\task\manager::scheduled_task_failed($task);
     } finally {
+        // Reset debugging if it changed.
+        if ($CFG->debug !== $debuglevel) {
+            set_debugging($debuglevel);
+        }
         // Reset back to the standard admin user.
         cron_setup_user();
         cron_set_process_title('Waiting for next scheduled task');
@@ -294,7 +304,8 @@ function cron_run_inner_scheduled_task(\core\task\task_base $task) {
  * @param \core\task\adhoc_task $task
  */
 function cron_run_inner_adhoc_task(\core\task\adhoc_task $task) {
-    global $DB, $CFG;
+    global $CFG, $DB;
+    $debuglevel = $CFG->debug;
 
     \core\task\manager::adhoc_task_starting($task);
     \core\task\logmanager::start_logging($task);
@@ -338,6 +349,11 @@ function cron_run_inner_adhoc_task(\core\task\adhoc_task $task) {
     try {
         get_mailer('buffer');
         cron_prepare_core_renderer();
+        // Temporarily increase debug level if task has failed and debugging isn't already at maximum.
+        if ($debuglevel !== DEBUG_DEVELOPER && $faildelay = $task->get_fail_delay()) {
+            mtrace('Debugging increased temporarily due to faildelay of ' . $faildelay);
+            set_debugging(DEBUG_DEVELOPER);
+        }
         $task->execute();
         if ($DB->is_transaction_started()) {
             throw new coding_exception("Task left transaction open");
@@ -368,6 +384,10 @@ function cron_run_inner_adhoc_task(\core\task\adhoc_task $task) {
         }
         \core\task\manager::adhoc_task_failed($task);
     } finally {
+        // Reset debug level if it changed.
+        if ($CFG->debug !== $debuglevel) {
+            set_debugging($debuglevel);
+        }
         // Reset back to the standard admin user.
         cron_setup_user();
         cron_prepare_core_renderer(true);