我正在尝试在 Windows 上安装适用于 capybara 的 webkit 驱动程序，但出现以下错误：
$ gem install capybara-webkit-0.12.1.gem
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
ERROR: Error installing capybara-webkit-0.12.1.gem:
ERROR: Failed to build gem native extension.
c:/RailsInstaller/Ruby1.9.3/bin/ruby.exe extconf.rb
Gem files will remain installed in c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/capybara-webkit-0.12.1 for inspection.
Results logged to c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/capybara-webkit-0.12.1/./gem_make.out
这是日志文件中的内容：
C:\>cat c:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/capybara-webkit-0.12.1/./gem_make.out
c:/RailsInstaller/Ruby1.9.3/bin/ruby.exe extconf.rb
我一直在尝试一段时间来找出问题所在。日志文件不是很有帮助，我发现的类似问题的解决方案要么特定于 Unix，要么对我不起作用。我很感激你能给我的任何帮助。
注意：此问题已交叉发布到capybara-webkit Google 组。
更新：我尝试在 capybara-webkit Google Group上的 Joe Ferris 的建议下手动构建 gem ，并设法获得了有关导致构建失败的原因的更多详细信息。这是我bundle exec rake build在 capybara-webkit 的目录中执行时收到的消息：
cd src/ && c:/Qt/4.8.3/bin/qmake.exe "c:/Documents and Settings/user/My Documents/Workspace/thoughtbot-capybara-webkit-7289a8e/src/webkit_server.pro" -spec c:/Qt/4.8.3/mkspecs/win32-g++ -o Makefile.webkit_server
'.' is not recognized as an internal or external command,
operable program or batch file.
'.' is not recognized as an internal or external command,
operable program or batch file.
capybara-webkit 0.12.0 built to pkg/capybara-webkit-0.12.0.gem
cd src/ && make -f Makefile.webkit_server
make[1]: Entering directory `/c/Documents and Settings/user/My Documents/Workspace/thoughtbot-capybara-webkit-7289a8e/src'
make -f Makefile.webkit_server.Release
make[2]: Entering directory `/c/Documents and Settings/user/My Documents/Workspace/thoughtbot-capybara-webkit-7289a8e/src'
bin/rcc.exe -name webkit_server webkit_server.qrc -o release/qrc_webkit_server.cpp
make[2]: bin/rcc.exe: Command not found
make[2]: *** [release/qrc_webkit_server.cpp] Error 127
make[2]: Leaving directory `/c/Documents and Settings/user/My Documents/Workspace/thoughtbot-capybara-webkit-7289a8e/src'
make[1]: *** [release] Error 2
make[1]: Leaving directory `/c/Documents and Settings/user/My Documents/Workspace/thoughtbot-capybara-webkit-7289a8e/src'
make: *** [sub-src-webkit_server-pro-make_default-ordered] Error 2
Command 'make' failed
其他可能相关的信息：
C:\>which make --all
C:\RailsInstaller\DevKit\bin\make.EXE
C:\Qt\4.8.3\bin\make.BAT
C:\Program Files\Gow\bin\make.EXE
C:\>which rcc
C:\Qt\4.8.3\bin\rcc.EXE
C:\>which g++
C:\RailsInstaller\DevKit\mingw\bin\g++.EXE
我的路径：
C:\PROGRA~1\Serena\vm\win32\bin;
C:\PROGRA~1\Serena\vm\common\bin\win32;
C:\WINDOWS\system32;
C:\WINDOWS;
C:\WINDOWS\System32\Wbem;
C:\Program Files\ATI Technologies\ATI.ACE\;
C:\Program Files\Microsoft SQL Server\80\Tools\Binn\;
C:\WINDOWS\system32\WindowsPowerShell\v1.0;
C:\Program Files\TortoiseSVN\bin;
C:\RailsInstaller\Ruby1.9.3\bin;
C:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\bin;
C:\RailsInstaller\DevKit\bin;
C:\RailsInstaller\Git\cmd;
C:\Program Files\ansi153\x86;
C:\bin;
C:\RailsInstaller\DevKit\mingw\bin;
C:\Qt\4.8.3\bin;
C:\Program Files\Nodejs;
C:\Documents and Settings\user\Desktop\emacs-23.4\bin;
C:\Python27;
C:\Python27\Scripts;
C:\Program Files\GnuWin32\bin;
C:\Program Files\Gow\bin;
C:\Program Files\Notepad++;
C:\Documents and Settings\user\Application Data\npm\