所以我有这个问题，libv8-3.16.14.3 无法安装，即使它欺骗性地告诉你它确实安装了。
所以问题的第一个迹象是当它发生时：
An error occurred while installing libv8 (3.16.14.3), and Bundler cannot continue.
Make sure that `gem install libv8 -v '3.16.14.3'` succeeds before bundling.
在bundle install.所以我做了一些谷歌搜索，并在运行时遇到了这个响应：
gem install libv8 -v '3.16.14.3' -- --with-system-v8
Building native extensions with: '--with-system-v8'
This could take a while...
Successfully installed libv8-3.16.14.3
Parsing documentation for libv8-3.16.14.3
Done installing documentation for libv8 after 1 seconds
1 gem installed
引导您认为它有效。 但是再次运行bundle install并看到有问题的错误
An error occurred while installing libv8 (3.16.14.3), and Bundler cannot continue.
Make sure that `gem install libv8 -v '3.16.14.3'` succeeds before bundling.
整个跟踪日志如下所示（由运行bundle install导致）：
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/Users/Adam/.rvm/rubies/ruby-2.1.5/bin/ruby extconf.rb
creating Makefile
Compiling v8 for x64
Using python 2.7.6
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/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/vendor/v8/out/x64.release/obj.target/preparser_lib/src/cached-powers.o] Error 1
make: *** [x64.release] Error 2
/Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/ext/libv8/location.rb:36:in `block in verify_installation!': libv8 did not install properly, expected binary v8 archive '/Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/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/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/ext/libv8/location.rb:35:in `each'
from /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/ext/libv8/location.rb:35:in `verify_installation!'
from /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/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_enable_backtrace=1 -Dv8_can_use_vfp2_instructions=true -Darm_fpu=vfpv2 -Dv8_can_use_vfp3_instructions=true -Darm_fpu=vfpv3
CXX(target) /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/vendor/v8/out/x64.release/obj.target/preparser_lib/src/allocation.o
CXX(target) /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/vendor/v8/out/x64.release/obj.target/preparser_lib/src/atomicops_internals_x86_gcc.o
CXX(target) /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/vendor/v8/out/x64.release/obj.target/preparser_lib/src/bignum.o
CXX(target) /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/vendor/v8/out/x64.release/obj.target/preparser_lib/src/bignum-dtoa.o
CXX(target) /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3/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/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/gems/libv8-3.16.14.3 for inspection.
Results logged to /Users/Adam/Dropbox/AisisGit/AisisPlatform/.bundle/gems/extensions/x86_64-darwin-14/2.1.0/libv8-3.16.14.3/gem_make.out
An error occurred while installing libv8 (3.16.14.3), and Bundler cannot continue.
Make sure that `gem install libv8 -v '3.16.14.3'` succeeds before bundling.
这是怎么回事。
注意：我在Mac上执行所有这些操作。
我首先使用 Homebrew 安装 V8 来解决这个问题：
$ brew install v8
然后运行您在Google上找到的提到的命令：
$ gem install libv8 -v '3.16.14.3' -- --with-system-v8
最后重新运行捆绑包安装：
$ bundle install
这个错误在使用 therubyracer 的项目中很常见，其他答案并没有为我解决它。不过他们帮了忙。安装顺序似乎是线索。
$ gem uninstall libv8
Successfully uninstalled libv8-3.16.14.13
$ gem install therubyracer -v '0.12.2'
2 gems installed
$ bundle
CRASH
$ gem install libv8 -v '3.16.14.13' -- --with-system-v8
Successfully installed libv8-3.16.14.13
1 gem installed
$ bundle
SUKSESS
去想一想，这很糟糕。但它为我解决了这个问题。
正如其他人所建议的：
$ brew install v8
$ gem install libv8 -v '3.16.14.3' -- --with-system-v8
$ bundle install
如果这不起作用，请尝试运行 bundle update 。
此外，运行bundle update是它工作的唯一方式