Issue #9937 has been updated by David Rodrguez. Hi Koichi, I've revisited this. This is not a bug in the TracePoint API. itwas a bug in Byebug. I was using the same callback for the RUBY_EVENT_B_CALL, RUBY_EVENT_CLASS and RUBY_EVENT_CALL, but only the RUBY_EVENT_CALL provides a method_id, so the other events were failing when trying to grab the method_id. The issue can be closed. ---------------------------------------- Bug #9937: Segfault in the TracePoint API https://bugs.ruby-lang.org/issues/9937#change-50194 * Author: David Rodrguez * Status: Assigned * Priority: Normal * Assignee: Koichi Sasada * Category: * Target version: * ruby -v: ruby 2.2.0dev (2014-06-12 trunk 46413) [i686-linux] * Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN ---------------------------------------- Hi! It seems that a regression bug has been recently introduced in the TracePoint API (maybe after changeset r45758). byebug's test suite works against 2.0 and 2.1, but segfaults against ruby-head. See https://travis-ci.org/deivid-rodriguez/byebug Segfault occurs in https://github.com/deivid-rodriguez/byebug/blob/master/ext/byebug/byebug.c#L252, I'm guessing the method ID provided by the TracePoint API is nil, so the SYM2ID call fails. I'm sorry I'm not currently able to properly investigate this. -- https://bugs.ruby-lang.org/