运行rake db后出现以下错误：migrate
rake aborted!
LoadError: dlopen(/Users/scott/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/mysql2-0.4.10/lib/mysql2/mysql2.bundle, 9): Library not loaded: libssl.1.0.0.dylib
Referenced from: /Users/scott/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/mysql2-0.4.10/lib/mysql2/mysql2.bundle
Reason: image not found - /Users/scott/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/mysql2-0.4.10/lib/mysql2/mysql2.bundle
/Users/scott/Google Drive/playground/myApp/myApp/config/application.rb:21:in `<top (required)>'
/Users/scott/Google Drive/playground/myApp/myApp/Rakefile:4:in `<top (required)>'
libssl指的是什么？
首先卸载mysql2-gem:
gem uninstall mysql2
确保您安装了openssl:
brew install openssl
它会打印出一些笔记。我们对这个部分感兴趣：
For compilers to find this software you may need to set:
LDFLAGS: -L/usr/local/opt/openssl/lib
CPPFLAGS: -I/usr/local/opt/openssl/include
然后你可以像这样重新安装mysql2-gem：
gem install mysql2 -v 0.4.10 -- --with-cppflags=-I/usr/local/opt/openssl/include --with-ldflags=-L/usr/local/opt/openssl/lib
你应该准备好了。
以下修复程序解决了问题
==> cd /usr/local/Cellar/openssl/1.0.2s/lib/
==> sudo cp libssl.1.0.0.dylib libcrypto.1.0.0.dylib /usr/local/lib
所以我自己的问题的答案是以下-在stackoverflow上的5个左右的其他解决方案中，这是唯一有效的：
brew install openssl
cd /usr/local/Cellar/openssl/1.0.1f/lib
sudo cp libssl.1.0.0.dylib libcrypto.1.0.0.dylib /usr/lib/
此处提供完整的解决方案-https://mithun.co/hacks/library-not-loaded-libcrypto-1-0-0-dylib-issue-in-mac/
在我的例子中，仅仅卸载和安装mysql2-gem就完成了
$ gem uninstall mysql2
$ bundle install
> Fetching mysql2 0.4.10
> Installing mysql2 0.4.10 with native extensions
只有一个命令：
gem pristine mysql2
然后我解决这个问题
对于rbenv:的用户
brew uninstall openssl
brew install rbenv/tap/openssl@1.0
gem uninstall mysql2
gem install mysql2 -v '0.4.10' -- --with-opt-dir="$(brew --prefix rbenv/tap/openssl@1.0)"
对我来说，mysql2的后续版本(在我的例子中是0.5.3(需要openssl1.1。做了这些之后，它对我起了作用：
$ cp /usr/local/Cellar/openssl@1.1/1.1.1j/lib/libssl.1.1.dylib /usr/local/lib
$ cp /usr/local/Cellar/openssl@1.1/1.1.1j/lib/libcrypto.1.1.dylib /usr/local/lib