无法为 Rails 项目安装 mysql2 gem

Question

我已经查看并尝试了 Stackoverflow.com 上有关该主题的所有内容，但仍然无法弄清楚...

当我“gem install mysql2”时出现权限错误。当我“sudo gem install mysql2”时，我得到以下信息：

    Teds-MacBook-Pro:~ tedmartin$ sudo gem install mysql2
Building native extensions.  This could take a while...
ERROR:  Error installing mysql2:
    ERROR: Failed to build gem native extension.

    current directory: /Users/tedmartin/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/mysql2-0.4.5/ext/mysql2
/Users/tedmartin/.rbenv/versions/2.4.1/bin/ruby -r ./siteconf20170420-50202-1nekuvd.rb extconf.rb
checking for rb_absint_size()... yes
checking for rb_absint_singlebit_p()... yes
checking for ruby/thread.h... yes
checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
checking for rb_thread_blocking_region()... no
checking for rb_wait_for_single_fd()... yes
checking for rb_hash_dup()... yes
checking for rb_intern3()... yes
checking for rb_big_cmp()... yes
-----
Using mysql_config at /usr/local/bin/mysql_config
-----
checking for mysql.h... yes
checking for SSL_MODE_DISABLED in mysql.h... yes
checking for SSL_MODE_PREFERRED in mysql.h... yes
checking for SSL_MODE_REQUIRED in mysql.h... yes
checking for SSL_MODE_VERIFY_CA in mysql.h... yes
checking for SSL_MODE_VERIFY_IDENTITY in mysql.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
-----
Don't know how to set rpath on your system, if MySQL libraries are not in path mysql2 may not load
-----
-----
Setting libpath to /usr/local/Cellar/mysql-connector-c/6.1.9/lib
-----
creating Makefile

current directory: /Users/tedmartin/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/mysql2-0.4.5/ext/mysql2
make "DESTDIR=" clean

current directory: /Users/tedmartin/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/mysql2-0.4.5/ext/mysql2
make "DESTDIR="
compiling client.c
compiling infile.c
compiling mysql2_ext.c
compiling result.c
compiling statement.c
linking shared-object mysql2/mysql2.bundle
ld: library not found for -l-lpthread
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [mysql2.bundle] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/tedmartin/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/mysql2-0.4.5 for inspection.
Results logged to /Users/tedmartin/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/extensions/x86_64-darwin-15/2.4.0-static/mysql2-0.4.5/gem_make.out

任何有想法、建议、提示、修复等的人......我将不胜感激。

谢谢！

Answer 1

这在 macOS Catalina 上对我有用：

确保您已安装 openssl。如果没有：

brew install openssl

然后进行 gem 安装：

gem install mysql2 -- --with-opt-dir="$(brew --prefix openssl)"

Answer 2

疯了 2 小时后它为我工作了

1. 卸载 Ruby 并安装 Ruby v2.6.6
2. 以管理员身份运行命令行gem install mysql2
3. 安装导轨gem install rails
4. 创建新项目rails new my_proj -d mysql

在 Windown 中 100% 工作

Answer 3

我在 Mojave 上遇到了同样的问题，以前的答案都没有对我有用，但是这个 Github 问题comment 中提到的命令确实有效

第 1 步。

brew install openssl

第 2 步。

export LIBRARY_PATH=$LIBRARY_PATH:/usr/local/opt/openssl/lib/

在我的例子中，我已经安装了openssl，所以真正解决问题的是导出命令。

Answer 4

1. 确保通过 Homebrew 在 Mac 上安装了 openssl。

brew install openssl

1. 安装 mysql2 gem。

gem install mysql2 -v '0.5.2' -- --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include

1. 如果bug没有修复，上面这个解决方案是最后一个

sudo installer -pkg /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg -target /

如果上述方法不起作用，另一种解决方案。

cd /usr/local/Cellar/openssl/1.0.2s/lib/

sudo cp libssl.1.0.0.dylib libcrypto.1.0.0.dylib /usr/local/lib

Answer 5

从this question 的答案中，运行以下对我有用

gem install mysql2 --source 'https://rubygems.org/' -- --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include

Answer 6

试试这个：

which mysql

然后，使用 output-result 使用现有的 mysql 安装目录安装 gem：

gem install mysql2 -- --with-mysql-dir=<mysql-installation-directory>