rackup -D breakage

[candlerb]

Just wanted to report some breakage when upgrading a system from
rack-1.0.1 to rack-1.1.0

It seems that rackup -D is now forcing a change directory to root. As
a result:

(1)
rackup .....orig_params..... -D

failed with no obvious error; stracing the process showed that it was
failing to open config.ru

So this is fixable by changing it to

rackup .....orig_params..... -D /path/to/config.ru

(2)
But then my app failed because 'require "foo"' couldn't find library
foo. So I had to change the config.ru itself to say:

APP_ROOT = File.expand_path(File.dirname(__FILE__))
Dir.chdir APP_ROOT
...

It's not a big issue now I know what the problem is, but I thought I'd
report it anyway, as it took some head-scratching to fix. Running the
app in foreground mode wasn't any help, because in that mode it was
working just fine!

Regards,

Brian.