按照这里的步骤"gem install therubyracer -v '0.10.2'" on osx mavericks not installing，我能够得到therubyracer -v 0.10.2和0.12.0安装正常，但不是0.11.4。
gem install therubyracer -v 0.11.4
返回：
Building native extensions. This could take a while...
ERROR: Error installing therubyracer:
ERROR: Failed to build gem native extension.
/Users/thooper/.rbenv/versions/2.1.2/bin/ruby -r ./siteconf20150102-7132-9ct9a4.rb extconf.rb
creating Makefile
Compiling v8 for x64
Using python 2.7.9
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Unable to find a compiler officially supported by v8.
It is recommended to use GCC v4.4 or higher
Using compiler: g++
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Unable to find a compiler officially supported by v8.
It is recommended to use GCC v4.4 or higher
../src/cached-powers.cc:136:18: error: unused variable 'kCachedPowersLength' [-Werror,-Wunused-const-variable]
static const int kCachedPowersLength = ARRAY_SIZE(kCachedPowers);
^
1 error generated.
make[1]: *** [/Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/vendor/v8/out/x64.release/obj.target/preparser_lib/src/cached-powers.o] Error 1
make: *** [x64.release] Error 2
/Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/ext/libv8/location.rb:36:in `block in verify_installation!': libv8 did not install properly, expected binary v8 archive '/Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/vendor/v8/out/x64.release/obj.target/tools/gyp/libv8_base.a'to exist, but it was not found (Libv8::Location::Vendor::ArchiveNotFound)
from /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/ext/libv8/location.rb:35:in `each'
from /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/ext/libv8/location.rb:35:in `verify_installation!'
from /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/ext/libv8/location.rb:26:in `install!'
from extconf.rb:7:in `<main>'
GYP_GENERATORS=make \
build/gyp/gyp --generator-output="out" build/all.gyp \
-Ibuild/standalone.gypi --depth=. \
-Dv8_target_arch=x64 \
-S.x64 -Dv8_can_use_vfp_instructions=true
CXX(target) /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/vendor/v8/out/x64.release/obj.target/preparser_lib/src/allocation.o
CXX(target) /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/vendor/v8/out/x64.release/obj.target/preparser_lib/src/atomicops_internals_x86_gcc.o
CXX(target) /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/vendor/v8/out/x64.release/obj.target/preparser_lib/src/bignum.o
CXX(target) /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/vendor/v8/out/x64.release/obj.target/preparser_lib/src/bignum-dtoa.o
CXX(target) /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17/vendor/v8/out/x64.release/obj.target/preparser_lib/src/cached-powers.o
extconf failed, exit code 1
Gem files will remain installed in /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/libv8-3.11.8.17 for inspection.
Results logged to /Users/thooper/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/extensions/x86_64-darwin-14/2.1.0-static/libv8-3.11.8.17/gem_make.out
答案 0 :(得分：4)
我终于得到了therubyracer 0.11.4来安装和使用Xcode 6.1.1,6.2 beta或6.3 beta（我测试了所有3个）以及Xcode 4.6.3（可在https://developer.apple.com/downloads/index.action获得）然后运行：
# rename your current version of Xcode to make it distinguishable
sudo mv /Applications/Xcode.app /Applications/$(xcodebuild -version | head -1 | sed -e 's/ //').app
# Download and install Xcode 4.6.3 and run:
sudo mv /Applications/Xcode.app /Applications/Xcode4.6.3.app
# Switch to your 4.6.3 version of Xcode
sudo xcode-select --switch /Applications/Xcode4.6.3.app
# Install the version of libv8 that's tied to your version of TRR:
gem install libv8 -v '3.11.8.17'
# Switch back to you original version of Xcode
sudo xcode-select --switch /Applications/Xcode6.x.app
# Install TRR
gem install therubyracer -v '0.11.4'
答案 1 :(得分：2)
这正是我遇到的问题，我用homebrew-versions解决了它。
我在安装gem libv8时遇到了麻烦。为了解决这个问题，我通过brew在我的系统上安装了v8，然后使用了选项--with-system-v8。
$ brew install v8
$ gem install libv8 -v '3.11.8.13' -- --with-system-v8
$ gem install therubyracer -v '0.11.4'
安装宝石libv8没有问题，但最后一行导致原始问题的错误。然后我尝试了，
$ gem install therubyracer -v '0.11.4' -- --with-system-v8 --with-v8-dir=/usr/local/Cellar/v8/3.30.33.16
指向brew提供的v8。在这种情况下，错误发生了变化，现在告诉我，我没有提供与3.11.8.13兼容的v8版本。
对于那些用Google搜索错误消息的人：
Building native extensions with: '--with-v8-dir=/usr/local/Cellar/v8/3.30.33.16/'
This could take a while...
ERROR: Error installing therubyracer:
ERROR: Failed to build gem native extension.
/Users/zeigfreid/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb --with-v8-dir=/usr/local/Cellar/v8/3.30.33.16/
checking for main() in -lpthread... yes
checking for main() in -lobjc... yes
checking for v8.h... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.
Provided configuration options:
--with-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/Users/zeigfreid/.rvm/rubies/ruby-1.9.3-p194/bin/ruby
--with-pthreadlib
--without-pthreadlib
--with-objclib
--without-objclib
--enable-debug
--disable-debug
--with-v8-dir
--with-v8-include
--without-v8-include=${v8-dir}/include
--with-v8-lib
--without-v8-lib=${v8-dir}/lib
/Users/zeigfreid/.rvm/gems/ruby-1.9.3-p194@va_rails_3.2.11/gems/libv8-3.11.8.13/ext/libv8/location.rb:50:in `configure': You have chosen to use the version of V8 found on your system (Libv8::Location::System::NotFoundError)
and *not* the one that is bundle with the libv8 rubygem. However,
it could not be located. please make sure you have a version of
v8 that is compatible with 3.11.8.13 installed. You may
need to special --with-v8-dir options if it is in a non-standard
location
thanks,
The Mgmt
from /Users/zeigfreid/.rvm/gems/ruby-1.9.3-p194@va_rails_3.2.11/gems/libv8-3.11.8.13/lib/libv8.rb:7:in `configure_makefile'
from extconf.rb:32:in `<main>'
extconf failed, exit code 1
Gem files will remain installed in /Users/zeigfreid/.rvm/gems/ruby-1.9.3-p194@va_rails_3.2.11/gems/therubyracer-0.11.4 for inspection.
Results logged to /Users/zeigfreid/.rvm/gems/ruby-1.9.3-p194@va_rails_3.2.11/extensions/x86_64-darwin-13/1.9.1/therubyracer-0.11.4/gem_make.out
我决定尝试安装早期版本的v8。再次使用brew，
$ brew search v8
homebrew/versions/v8-315 v8
$ brew install v8-315
$ brew info v8-315
$ gem install therubyracer -v '0.11.4' -- --with-system-v8 --with-v8-dir=/usr/local/Cellar/v8-315/3.15.11
这很有用。我最终安装的v8版本是~3.15，但这与3.11.8兼容
这里的真正解决方案是将所有内容更新到最新版本，我不主张使用旧的和过时的宝石。保持系统清洁和最新，即使它很痛！
答案 2 :(得分：0)
此行在您的错误消息中出现几次：
It is recommended to use GCC v4.4 or higher
您所采取步骤的链接表示运行brew install apple-gcc42，可能会安装GCC 4.2。 4.2小于4.4。
C源产生的具体错误似乎是：
../src/cached-powers.cc:136:18: error: unused variable 'kCachedPowersLength' [-Werror,-Wunused-const-variable]
因此，如果您可以以某种方式编辑makefile（或extconf.rb）以删除这些标志，那么这也可能有效。但是我建议安装兼容的编译器，因为修改cflags似乎有点hacky。