Sasada,
  I wanted to try out Rails against the latest YARV. I'm running YARV revision 475, latest stable cygwin, Widnows XP SP 2, Rails 1.0.0.

I ran into the following when I tried the "about this application's environment" on the default index.html file for rails projects:

$ /usr/local/bin/ruby script/server
=> Booting WEBrick...
=> Rails application started on http://0.0.0.0:3000
=> Ctrl-C to shutdown server; call with --help for options
[2006-02-23 16:08:55] INFO  WEBrick 1.3.1
[2006-02-23 16:08:55] INFO  ruby 2.0.0 (2006-02-14) [i386-cygwin]
[2006-02-23 16:08:55] INFO  WEBrick::HTTPServer#start: pid=1940 port=3000
127.0.0.1 - - [23/Feb/2006:16:09:09 GMT-5:00] "GET / HTTP/1.1" 500 5504
- -> /
127.0.0.1 - - [23/Feb/2006:16:14:06 GMT-5:00] "GET / HTTP/1.1" 200 7551
- -> /
127.0.0.1 - - [23/Feb/2006:16:14:06 GMT-5:00] "GET /javascripts/prototype.js HTT
P/1.1" 304 0
http://localhost:3000/ -> /javascripts/prototype.js
127.0.0.1 - - [23/Feb/2006:16:14:06 GMT-5:00] "GET /javascripts/effects.js HTTP/
1.1" 304 0
http://localhost:3000/ -> /javascripts/effects.js
127.0.0.1 - - [23/Feb/2006:16:14:06 GMT-5:00] "GET /images/rails.png HTTP/1.1" 2
00 1787
http://localhost:3000/ -> /images/rails.png
/usr/local/ruby/lib/ruby/gems/2.0/gems/activesupport-1.2.5/lib/active_support/de
pendencies.rb:134: -- stack frame ------------
0xbc90008 (0000): 00000001
0xbc9000c (0001): 0593be28
0xbc90010 (0002): 00000004
0xbc90014 (0003): 00000004
0xbc90018 (0004): 10d1ad2d
0xbc9001c (0005): 05969350
0xbc90020 (0006): 0593bf00
0xbc90024 (0007): 05b78660
0xbc90028 (0008): 05b78348
0xbc9002c (0009): 05969350
0xbc90030 (0010): 05b77100
0xbc90034 (0011): 00000004
0xbc90038 (0012): 00000004
0xbc9003c (0013): 00000004
0xbc90040 (0014): 00000004
0xbc90044 (0015): 00000001
0xbc90048 (0016): 05969350
0xbc90050 (0018): 05b78660
0xbc90054 (0019): 05969728
0xbc90058 (0020): 05968d98
0xbc9005c (0021): 05b7e2a0
0xbc90060 (0022): 05b7e240
0xbc90064 (0023): 05b7df58
0xbc90068 (0024): 00000004
0xbc9006c (0025): 00000001
0xbc90070 (0026): 05b7df58
0xbc90074 (0027): 05b78348
0xbc90078 (0028): 05b78660
0xbc9007c (0029): 00000004
0xbc90080 (0030): 00000001
0xbc90084 (0031): 05b7df58
0xbc90088 (0032): 05b78348
0xbc9008c (0033): 05b78660
0xbc90090 (0034): 00000004
0xbc90094 (0035): 05b7c8d8
0xbc90098 (0036): 00000004
0xbc9009c (0037): 00000004
0xbc900a0 (0038): 00000004
0xbc900a4 (0039): 00000004
0xbc900a8 (0040): 00000001
0xbc900ac (0041): 05965258
0xbc900b0 (0042): 05b799f8
0xbc900b4 (0043): 04d86c78
0xbc900b8 (0044): 05b7c8d8
0xbc900bc (0045): 05b760f8
0xbc900c0 (0046): 05b760c8
0xbc900c4 (0047): 00000004
0xbc900c8 (0048): 00000004
0xbc900cc (0049): 00000001
0xbc900d0 (0050): 05965258
0xbc900d4 (0051): 00000004
0xbc900d8 (0052): 00000001
0xbc900dc (0053): 05972308
0xbc900e0 (0054): 0147d50e
0xbc900e4 (0055): 05b05940
0xbc900e8 (0056): 05b05388
0xbc900ec (0057): 00000004
0xbc900f0 (0058): 00000001
0xbc900f4 (0059): 059722c0
0xbc900f8 (0060): 0bd0fe8d
0xbc900fc (0061): 00000001
0xbc90100 (0062): 059722a8
0xbc90104 (0063): 05b01158
0xbc90108 (0064): 00000004
0xbc9010c (0065): 00000004
0xbc90110 (0066): 00000004
0xbc90114 (0067): 0bc900f1 (= 58)
0xbc90118 (0068): 05972308
0xbc9011c (0069): 05b01158
0xbc90120 (0070): 00000004
0xbc90124 (0071): 00000001 <- lfp <- dfp
0xbc90128 (0072): 05972308 <- bp
0xbc9012c (0073): 05b01158
-- control frame ----------
c:0014 p:0009 s:0074 b:0072 l:0071 d:0071 METHOD i:load_file! s:
c:0013 p:0234 s:0068 b:0068 l:0058 d:0067 BLOCK  i:block in const_load! s:
   -
c:0012 p:-001 s:0063 b:0062 l:0061 d:0061 FINISH i:-        s:
c:0011 p:-001 s:0061 b:0061 l:0060 d:0060 CFUNC  i:each     s:
c:0010 p:0084 s:0059 b:0059 l:0058 d:0058 METHOD i:const_load! s:
c:0009 p:0077 s:0053 b:0053 l:0052 d:0052 METHOD i:prepare_application s:

c:0008 p:0091 s:0050 b:0050 l:0049 d:0049 METHOD i:dispatch s:
c:0007 p:0097 s:0041 b:0041 l:0040 d:0040 METHOD i:handle_dispatch s:

c:0006 p:0058 s:0031 b:0031 l:0030 d:0030 METHOD i:service  s:         -
c:0005 p:0238 s:0026 b:0026 l:0025 d:0025 METHOD i:service  s:
c:0004 p:0355 s:0016 b:0016 l:0015 d:0015 METHOD i:run      s:         -
c:0003 p:0112 s:0005 b:0005 l:0673 d:0004 PROC   i:block in start_thread s:
    -
c:0002 p:-001 s:0001 b:0001 l:0000 d:0000 FINISH i:-        s:         -
c:0001 p:-001 s:0000 b:-001 l:0000 d:0000 ------ i:-        s:         -
---------------------------
DBG> : "/usr/local/ruby/lib/ruby/gems/2.0/gems/activesupport-1.2.5/lib/active_su
pport/dependencies.rb:97:in `block in const_load!'"
DBG> : "/usr/local/ruby/lib/ruby/gems/2.0/gems/activesupport-1.2.5/lib/active_su
pport/dependencies.rb:80:in `each'"
DBG> : "/usr/local/ruby/lib/ruby/gems/2.0/gems/activesupport-1.2.5/lib/active_su
pport/dependencies.rb:80:in `const_load!'"
DBG> : "/usr/local/ruby/lib/ruby/gems/2.0/gems/rails-1.0.0/lib/dispatcher.rb:71:
in `prepare_application'"
DBG> : "/usr/local/ruby/lib/ruby/gems/2.0/gems/rails- 1.0.0/lib/dispatcher.rb:37:
in `dispatch'"
DBG> : "/usr/local/ruby/lib/ruby/gems/2.0/gems/rails-1.0.0/lib/webrick_server.rb
:117:in `handle_dispatch'"
DBG> : "/usr/local/ruby/lib/ruby/gems/2.0/gems/rails- 1.0.0/lib/webrick_server.rb
:83:in `service'"
DBG> : "/usr/local/ruby/lib/ruby/2.0/webrick/httpserver.rb:111:in `service'"
DBG> : "/usr/local/ruby/lib/ruby/2.0/webrick/httpserver.rb:70:in `run'"
DBG> : "/usr/local/ruby/lib/ruby/2.0/webrick/server.rb:173:in `block in start_th
read'"
[BUG] Segmentation fault
ruby 2.0.0 (2006-02-14) [i386-cygwin]

Aborted (core dumped)

Thanks,
Chris
--
http://cwilliams.textdriven.com