I just pushed a prerelease gem to RubyGems.org with the following changes. Please let us know if there were any other regressions in 4.0.0. Expect a final 4.0.1 release soonish... Full git changelog (pushed to git://bogomips.org/unicorn.git): commit 19f798301ac1884f423640efafb277b071bb5439 Author: Eric Wong <normalperson at yhbt.net> Date: Wed Jun 29 07:19:32 2011 +0000 fix per-worker listen directive in after_fork hook The testcase for this was broken, too, so we didn''t notice this :< Reported-by: ghazel at gmail.com on the Rainbows! mailing list, http://mid.gmane.org/BANLkTi=oQXK5Casq9SuGD3edeUrDPvRm3A at mail.gmail.com commit 38672501206c9e64d241e3d8571f70b198f0c1e5 Author: Eric Wong <normalperson at yhbt.net> Date: Mon Jun 27 20:51:16 2011 +0000 configurator: truncate timeouts to 32-bit LONG_MAX IO.select in Ruby can''t wait longer than this. This means Unicorn can''t support applications that take longer than 68 years to respond :( -- Eric Wong