• Debug logging
• Send logging to non-default FILE
• Dump a trace event or range of events
• Be sure to load the right executable image for gdb'ing a tracee
• Dump a full tracee tree with pstree
• Dump attributes of tracee tasks in rr debugger session
• Force rr to always launch a gdbserver, even if it thinks that's a bad idea
• Use assert_exec() to launch a gdbserver for a tracee
• Look up a Task whose (recorded!) tid you know
• Launch a gdbserver for arbitrary tasks at arbitrary times
• rr and tracees can be debugged simultaneously
• Finding the precise event during recording at which some tracee state changes
• Test failures that only reproduce during "make check"
• You may find this helper repository useful