Here's my latest clone and build-fail:

C:\Sites>git clone https://github.com/railsbridge/docs.git
Cloning into 'docs'...
remote: Counting objects: 2365, done.
remote: Compressing objects: 100% (931/931), done.
remote: Total 2365 (delta 1489), reused 2286 (delta 1416)Receiving objects:  88% (2082/2365), 7.12 M
iB | 1.23 MiB/s
Receiving objects: 100% (2365/2365), 7.81 MiB | 1.20 MiB/s, done.
Resolving deltas: 100% (1489/1489), done.

C:\Sites>cd docs

C:\Sites\docs>bundle install
Fetching source index for http://rubygems.org/
Using rake (0.9.2.2)
Using ZenTest (4.7.0)
Using RubyInline (3.11.2)
Using sexp_processor (3.1.0)
Using ParseTree (3.0.8)
Using sass (3.1.15)
Using bourbon (1.4.0)
Using coderay (1.0.5)
Using daemons (1.1.8)
Using polyglot (0.3.3)
Using treetop (1.4.10)
Using erector (0.9.0.pre1)
Using json (1.6.6)
Using nokogiri (1.5.2)
Using rack (1.4.1)
Using rack-codehighlighter (0.5.0)
Using redcarpet (2.1.1)
Using trollop (1.16.2)
Using deckrb (0.3.0)
Using diff-lcs (1.1.3)
Installing eventmachine (0.12.10) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

        C:/RailsInstaller/Ruby1.9.3/bin/ruby.exe extconf.rb
checking for rb_trap_immediate in ruby.h,rubysig.h... no
checking for rb_thread_blocking_region()... yes
checking for inotify_init() in sys/inotify.h... no
checking for __NR_inotify_init in sys/syscall.h... no
checking for writev() in sys/uio.h... no
checking for rb_thread_check_ints()... yes
checking for rb_time_new()... yes
checking for windows.h... yes
checking for winsock.h... yes
checking for main() in -lkernel32... yes
checking for main() in -lrpcrt4... yes
checking for main() in -lgdi32... yes
checking for main() in -lssl... no
creating Makefile

make
generating rubyeventmachine-i386-mingw32.def
compiling binder.cpp
cc1plus.exe: warning: command line option "-Wdeclaration-after-statement" is valid for C/ObjC but no
t for C++
cc1plus.exe: warning: command line option "-Wimplicit-function-declaration" is valid for C/ObjC but
not for C++
In file included from project.h:137:0,
                 from binder.cpp:20:
binder.h:35:34: warning: type qualifiers ignored on function return type
In file included from project.h:138:0,
                 from binder.cpp:20:
em.h:91:47: warning: type qualifiers ignored on function return type
em.h:92:76: warning: type qualifiers ignored on function return type
em.h:93:56: warning: type qualifiers ignored on function return type
em.h:95:57: warning: type qualifiers ignored on function return type
em.h:96:60: warning: type qualifiers ignored on function return type
em.h:97:58: warning: type qualifiers ignored on function return type
em.h:98:55: warning: type qualifiers ignored on function return type
em.h:99:36: warning: type qualifiers ignored on function return type
em.h:101:47: warning: type qualifiers ignored on function return type
em.h:106:42: warning: type qualifiers ignored on function return type
em.h:123:45: warning: type qualifiers ignored on function return type
em.h:132:36: warning: type qualifiers ignored on function return type
In file included from project.h:145:0,
                 from binder.cpp:20:
eventmachine.h:45:61: warning: type qualifiers ignored on function return type
eventmachine.h:46:112: warning: type qualifiers ignored on function return type
eventmachine.h:47:69: warning: type qualifiers ignored on function return type
eventmachine.h:49:73: warning: type qualifiers ignored on function return type
eventmachine.h:62:75: warning: type qualifiers ignored on function return type
eventmachine.h:63:74: warning: type qualifiers ignored on function return type
eventmachine.h:64:77: warning: type qualifiers ignored on function return type
eventmachine.h:65:41: warning: type qualifiers ignored on function return type
In file included from project.h:145:0,
                 from binder.cpp:20:
eventmachine.h:99:60: warning: type qualifiers ignored on function return type
eventmachine.h:100:58: warning: type qualifiers ignored on function return type
eventmachine.h:102:60: warning: type qualifiers ignored on function return type
eventmachine.h:105:41: warning: type qualifiers ignored on function return type
compiling cmain.cpp
cc1plus.exe: warning: command line option "-Wdeclaration-after-statement" is valid for C/ObjC but no
t for C++
cc1plus.exe: warning: command line option "-Wimplicit-function-declaration" is valid for C/ObjC but
not for C++
In file included from project.h:137:0,
                 from cmain.cpp:20:
binder.h:35:34: warning: type qualifiers ignored on function return type
In file included from project.h:138:0,
                 from cmain.cpp:20:
em.h:91:47: warning: type qualifiers ignored on function return type
em.h:92:76: warning: type qualifiers ignored on function return type
em.h:93:56: warning: type qualifiers ignored on function return type
em.h:95:57: warning: type qualifiers ignored on function return type
em.h:96:60: warning: type qualifiers ignored on function return type
em.h:97:58: warning: type qualifiers ignored on function return type
em.h:98:55: warning: type qualifiers ignored on function return type
em.h:99:36: warning: type qualifiers ignored on function return type
em.h:101:47: warning: type qualifiers ignored on function return type
em.h:106:42: warning: type qualifiers ignored on function return type
em.h:123:45: warning: type qualifiers ignored on function return type
em.h:132:36: warning: type qualifiers ignored on function return type
In file included from project.h:145:0,
                 from cmain.cpp:20:
eventmachine.h:45:61: warning: type qualifiers ignored on function return type
eventmachine.h:46:112: warning: type qualifiers ignored on function return type
eventmachine.h:47:69: warning: type qualifiers ignored on function return type
eventmachine.h:49:73: warning: type qualifiers ignored on function return type
eventmachine.h:62:75: warning: type qualifiers ignored on function return type
eventmachine.h:63:74: warning: type qualifiers ignored on function return type
eventmachine.h:64:77: warning: type qualifiers ignored on function return type
eventmachine.h:65:41: warning: type qualifiers ignored on function return type
In file included from project.h:145:0,
                 from cmain.cpp:20:
eventmachine.h:99:60: warning: type qualifiers ignored on function return type
eventmachine.h:100:58: warning: type qualifiers ignored on function return type
eventmachine.h:102:60: warning: type qualifiers ignored on function return type
eventmachine.h:105:41: warning: type qualifiers ignored on function return type
cmain.cpp:98:71: warning: type qualifiers ignored on function return type
cmain.cpp:109:122: warning: type qualifiers ignored on function return type
cmain.cpp:119:79: warning: type qualifiers ignored on function return type
cmain.cpp:129:83: warning: type qualifiers ignored on function return type
cmain.cpp:260:85: warning: type qualifiers ignored on function return type
cmain.cpp:270:84: warning: type qualifiers ignored on function return type
cmain.cpp:280:88: warning: type qualifiers ignored on function return type
cmain.cpp:290:51: warning: type qualifiers ignored on function return type
cmain.cpp:300:70: warning: type qualifiers ignored on function return type
cmain.cpp:320:55: warning: type qualifiers ignored on function return type
cmain.cpp:546:70: warning: type qualifiers ignored on function return type
cmain.cpp:669:68: warning: type qualifiers ignored on function return type
cmain.cpp: In function 'int evma_send_file_data_to_connection(long unsigned int, const char*)':
cmain.cpp:752:6: error: cannot convert 'stat*' to '_stati64*' for argument '2' to 'int _fstati64(int
, _stati64*)'
make: *** [cmain.o] Error 1


Gem files will remain installed in C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/eventmachine
-0.12.10 for inspection.
Results logged to C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/eventmachine-0.12.10/ext/gem_
make.out
An error occured while installing eventmachine (0.12.10), and Bundler cannot continue.
Make sure that `gem install eventmachine -v '0.12.10'` succeeds before bundling.