Thursday, 4 February 2016

rr 4.1.0 Released

This release mainly improves replay performance dramatically, as I documented in November. It took a while to stabilize for release, partly because we ran into a kernel bug that caused rr tests (and sometimes real rr usage) to totally lock up machines. This release contains a workaround for that kernel bug. It also contains support for the gdb find command, and fixes for a number of other bugs.


  1. Unrelated to this release, but another thing that rr is really handy for: I needed to debug a gcc plugin. But 'gcc' is just a driver script. I was previously hacking this in by renaming cc1plus to cc1plus.real, then making a shell script named cc1plus that runs cc1plus.real under gdb.

    With rr, I can just rr record the toplevel invocation, then use rr ps and find the program I'm looking for. Not really a big deal compared to the core rr functionality, but it's really handy.

    1. It's true that debugging multiple processes with gdb is a nightmare.