How difficult would it be to allow the bootstrap process to use a preexisting Racket installation? This would alleviate some of the performance loss, for example in rebuilds by developers or in continuous integration. Sam <div class="gmail_quote">On Aug 11, 2014 11:16 PM, "Matthew Flatt" <<a href="mailto:mflatt@cs.utah.edu">mflatt@cs.utah.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> I've changed the Racket CGC implementation --- which is mostly used only to build the normal Racket variant --- to use SGC by default, instead of the Boehm GC. The intent of the switch is to make the more portable GC the default. If you have an existing build in a repo checkout, then `make` is likely to fail, because the makefile dependencies are not precise enough to deal with the switch. You can discard your old build directory, or it might work to simply delete <builddir>/racket/libmzgc.a If you're using CGC and want to continue using the Boehm GC, then provide `--disable-sgc` to `configure`. I've tuned SGC to bring its performance closer to the Boehm GC, but it's still slower. _________________________ Racket Developers list: <a href="http://lists.racket-lang.org/dev" target="_blank">http://lists.racket-lang.org/dev</a> </blockquote></div>