Update development docs to use 'thread apply all bt full'

fixes #11385

diff --git a/doc/21-development.md b/doc/21-development.md
index 62f3ba3e693c0d9503060f3caf117b55eadb8b82..204ac76c97bcb98c19f28203471d345e090f5776 100644 (file)
--- a/doc/21-development.md
+++ b/doc/21-development.md
@@ -156,12 +156,12 @@ a new gdb run.
 If Icinga 2 aborted its operation abnormally, generate a backtrace.
 
     (gdb) bt
-    (gdb) bt full
+    (gdb) thread apply all bt full
 
-Generate a full backtrace for all threads and store it into a new file
-(e.g. for debugging dead locks):
+If Icinga 2 is still running generate a full backtrace from the running
+process and store it into a new file (e.g. for debugging dead locks):
 
-    # gdb -p PID -batch -ex "thread apply all bt full" -ex "detach" -ex "q" > gdb_bt.log
+    # gdb -p $(pidof icinga2) -batch -ex "thread apply all bt full" -ex "detach" -ex "q" > gdb_bt.log
 
 If you're opening an issue at [https://dev.icinga.org] make sure
 to attach as much detail as possible.