Update acid test

[vladimyr]

Checklist

• documentation is changed or added
• commit message follows commit guidelines

Description of change

Joined two-step acid test into a single c/p-able shell snippet.

[vladimyr]

I've converted the acid test to a remote shell script and introduced custom git.io URL mapping:

curl https://git.io/ -i -F "url=https://raw.githubusercontent.com/nodejs/node-gyp/master/acid-test.sh" -F "code=node-gyp:acid-test"

As a result, end-users can simply invoke it using:

curl -L https://git.io/node-gyp:acid-test

[cclauss]

Homebrew now kicks out the following message:

Warning: A newer Command Line Tools release is available.
Update them from Software Update in System Preferences or run:
  softwareupdate --all --install --force

If that doesn't show you an update run:
  sudo rm -rf /Library/Developer/CommandLineTools
  sudo xcode-select --install

Alternatively, manually download them from:
  https://developer.apple.com/download/more/.

This worked like a champ for me. I did the first command and about 30 seconds later a macOS System Preferences/Software Update dialog box popped up asking me to perform an update.

com.apple.pkg.CLTools_Executables
com.apple.pkg.CLTools_SDK_macOS1015
com.apple.pkg.CLTools_SDK_macOS1014
com.apple.pkg.CLTools_macOS_SDK

Should we adopt this approach?

[vladimyr]

Homebrew now kicks out the following message:

Warning: A newer Command Line Tools release is available.
Update them from Software Update in System Preferences or run:
  softwareupdate --all --install --force

If that doesn't show you an update run:
  sudo rm -rf /Library/Developer/CommandLineTools
  sudo xcode-select --install

Alternatively, manually download them from:
  https://developer.apple.com/download/more/.

This worked like a champ for me. I did the first command and about 30 seconds later a macOS System Preferences/Software Update dialog box popped up asking me to perform an update.

@cclauss It happened to me too and I did the same except it totally corrupted my clt installation and the only way out was to remove it completely and manually install again by downloading from Apple's web (last resort described here). Simply put it isn't safe!

[rvagg]

f7bfce9

[vladimyr]

@rvagg Be warned that this isn't reliable at all. All of a sudden it gives me false negative on my own machine!

I essentially rewrote Python code that @cclauss pointed to in bash but that is yesterday news. Today's HB CLT detection looks much more sophisticated https://github.com/Homebrew/brew/blob/5fb158f/Library/Homebrew/os/mac/xcode.rb#L198-L326