http://sourceware.org/ml/gdb-patches/2016-03/msg00246.html
Subject: [patch] Suggest running gdbserver for a PID in container


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Hi,

currently
	gdb -p <pid from a container>
will print:
	warning: Target and debugger are in different PID namespaces; thread lists and other data are likely unreliable

BTW it is a bit lost in all the other messages.  Full screen output is in:
	https://sourceware.org/bugzilla/show_bug.cgi?id=19828

It correctly states the problem but it does not say how to solve it.

Is at least this little suggestion OK?

Originally I wanted to suggest also the Docker "-p 1234:1234" parameter but
I see the containers are more general topic than just Docker (even LxC etc.).

According to Gary future GDBs should be able to work even without gdbserver.
But currently gdbserver is still required.


Thanks,
Jan

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gdb/ChangeLog
2016-03-15  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* linux-thread-db.c (check_pid_namespace_match): Extend the message.

Index: gdb-7.6.1/gdb/linux-thread-db.c
===================================================================
--- gdb-7.6.1.orig/gdb/linux-thread-db.c	2016-03-17 22:06:28.765832372 +0100
+++ gdb-7.6.1/gdb/linux-thread-db.c	2016-03-17 22:07:06.918107721 +0100
@@ -1265,7 +1265,8 @@
 	{
 	  warning (_ ("Target and debugger are in different PID "
 		      "namespaces; thread lists and other data are "
-		      "likely unreliable"));
+		      "likely unreliable.  "
+		      "Connect to gdbserver inside the container."));
 	}
 
       xfree (our_pid_ns);