Eu me iniciei no desenvolvimento de trilhos ontem.
Eu instalei rubi 1.9.1, rubygems e trilhos.
Corridagem install mongrel funcionou bem e ostensivamente instalado mestiço também. Estou um pouco confuso porque:

script / servidor inicia webrick por padrãowhich mongrel não retorna nadalocate mongrel retorna muitas entradas como

/Developer/SDKs/MacOSX10.5.sdk/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/mongrel-1.0.1
/Developer/SDKs/MacOSX10.5.sdk/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib
/Developer/SDKs/MacOSX10.5.sdk/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel
.
.
.
/usr/local/bin/mongrel_rails
/usr/local/lib/ruby/gems/1.9.1/cache/mongrel-1.1.5.gem
/usr/local/lib/ruby/gems/1.9.1/doc/actionpack-2.3.2/rdoc/files/lib/action_controller/vendor/rack-1_0/rack/handler/evented_mongrel_rb.html
/usr/local/lib/ruby/gems/1.9.1/doc/actionpack-2.3.2/rdoc/files/lib/action_controller/vendor/rack-1_0/rack/handler/mongrel_rb.html
/usr/local/lib/ruby/gems/1.9.1/doc/actionpack-2.3.2/rdoc/files/lib/action_controller/vendor/rack-1_0/rack/handler/swiftiplied_mongrel_rb.html
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.2/lib/action_controller/vendor/rack-1.0/rack/handler/evented_mongrel.rb
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.2/lib/action_controller/vendor/rack-1.0/rack/handler/mongrel.rb
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-2.3.2/lib/action_controller/vendor/rack-1.0/rack/handler/swiftiplied_mongrel.rb
/usr/local/lib/ruby/gems/1.9.1/gems/mongrel-1.1.5
.
.
.

Parece que eu tenho mongrel instalado (tanto a instalação padrão e minha instalação personalizada). Então, por que o vira-lata não retorna alguma coisa?

Também tentando reinstalar usando mestiçogem install mongrel retorna lança seu próprio conjunto de exceções:

Building native extensions.  This could take a while...
ERROR:  Error installing mongrel:
    ERROR: Failed to build gem native extension.

/usr/local/bin/ruby extconf.rb install mongrel
checking for main() in -lc... yes
creating Makefile

make
gcc -I. -I/usr/local/include/ruby-1.9.1/i386-darwin9.7.0 -I/usr/local/include/ruby-1.9.1/ruby/backward -I/usr/local/include/ruby-1.9.1 -I. -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE   -fno-common -D_XOPEN_SOURCE=1 -O2 -g -Wall -Wno-parentheses  -fno-common -pipe -fno-common  -o http11.o -c http11.c
http11.c: In function 'http_field':
http11.c:77: error: 'struct RString' has no member named 'ptr'
http11.c:77: error: 'struct RString' has no member named 'len'
http11.c:77: warning: left-hand operand of comma expression has no effect
http11.c:77: warning: statement with no effect
http11.c: In function 'header_done':
http11.c:172: error: 'struct RString' has no member named 'ptr'
http11.c:174: error: 'struct RString' has no member named 'ptr'
http11.c:176: error: 'struct RString' has no member named 'ptr'
http11.c:177: error: 'struct RString' has no member named 'len'
http11.c: In function 'HttpParser_execute':
http11.c:298: error: 'struct RString' has no member named 'ptr'
http11.c:299: error: 'struct RString' has no member named 'len'
make: *** [http11.o] Error 1