安装rmagick 2.16.0
rmagick 需要老版本 imagemagick@6
brew search imagemagick@6
安装 brew install imagemagick@6
导入环境变量
This formula is keg-only, which means it was not symlinked into /usr/local,
because this is an alternate version of another formula.
If you need to have this software first in your PATH run:
echo 'export PATH="/usr/local/opt/imagemagick@6/bin:$PATH"' >> ~/.bash_profile
For compilers to find this software you may need to set:
LDFLAGS: -L/usr/local/opt/imagemagick@6/lib
CPPFLAGS: -I/usr/local/opt/imagemagick@6/include
For pkg-config to find this software you may need to set:
PKG_CONFIG_PATH: /usr/local/opt/imagemagick@6/lib/pkgconfig
export PKG_CONFIG_PATH=/usr/local/opt/imagemagick@6/lib/pkgconfig
gem install rmagick