运行rvm requirements命令时出现以下错误。
有人可以帮忙吗？我尝试了几种解决方案，但它没有用。
操作系统：MacOS Sierra 10.12.6
错误：
_$ rvm requirements
Checking requirements for osx.
Installing requirements for osx.
Updating system..........
Installing required packages: apple-gcc42..There were package installation errors, make sure to read the log.
Try brew tap --repair and make sure brew doctor looks reasonable.
Check Homebrew requirements https://github.com/Homebrew/homebrew/wiki/Installation
.
Error running 'requirements_osx_brew_libs_install apple-gcc42',
please read /Users//package_install_apple-gcc42.log
Requirements installation failed with status: 1._
我还尝试直接安装ruby并收到以下错误：
$ rvm install 2.4.0
Searching for binary rubies, this might take some time.
No binary rubies available for: osx/10.12/x86_64/ruby-2.4.0.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
You requested building with '/bin/gcc-4.2' but it is not in your path.