lib: explicitly initialize debuglog during bootstrap

This patch splits the implementation of util.debuglog into a
separate file and explicitly initialize it during pre-execution
since the initialization depends on environment variables.
Also delays the call to `debuglog` in modules that are loaded during
bootstrap to make sure we only access the environment variable
during pre-execution.

PR-URL: https://github.com/nodejs/node/pull/26468
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

1 files changed, 9 insertions, 1 deletions

diff --git a/lib/timers.js b/lib/timers.js
index a7c795701e..d57b1ceb3e 100644
--- a/lib/timers.js
+++ b/lib/timers.js
@@ -42,7 +42,15 @@ const {
 const internalUtil = require('internal/util');
 const util = require('util');
 const { ERR_INVALID_CALLBACK } = require('internal/errors').codes;
-const debug = util.debuglog('timer');
+
+let debuglog;
+function debug(...args) {
+  if (!debuglog) {
+    debuglog = require('internal/util/debuglog').debuglog('timer');
+  }
+  debuglog(...args);
+}
+
 const {
   destroyHooksExist,
   // The needed emit*() functions.