OSX解决The diff tool bc3 is not available as ‘bcompare‘

尝试使用 git 启动 Beyond Compare 时，出现此错误：

The diff tool bc3 is not available as 'bcompare'

fatal: external diff died, stopping at plugins/PushPlugin.m

其中，设置差异工具：

$ git config --global diff.tool bc3

尝试比较目录：

$ git difftool plugins

Viewing (1/2): 'plugins/PushPlugin.m'
Launch 'bc3' [Y/n]: y

解决方案：

启动 Beyond Compare，转到 Beyond Compare 菜单并运行安装命令行工具(Install Command Line Tools)。