Unable to install PHP 7 with Homebrew on macOS Sierra

I’m trying to setup Laravel’s Valet which, as a dependency, requires PHP 7. When I try to install PHP 7 with Homebrew I get the following error:

Configuring SAPI modules
checking for Apache 2.0 handler-module support via DSO through APXS... 

Sorry, I cannot run apxs.  Possible reasons follow:

1. Perl is not installed
2. apxs was not found. Try to pass the path using --with-apxs2=/path/to/apxs
3. Apache was not built using --enable-so (the apxs usage page is displayed)

The output of /usr/sbin/apxs follows:
apxs:Error: /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.12.xctoolchain/usr/local/bin/apr-1-config not found!.

configure: error: Aborting

READ THIS: https://git.io/brew-troubleshooting
If reporting this issue please do so at (not Homebrew/brew):
  https://github.com/Homebrew/homebrew-php/issues

These open issues may also help:
php70-dbase  https://github.com/Homebrew/homebrew-php/issues/3508
php70-intl not found https://github.com/Homebrew/homebrew-php/issues/3591
php70-opcache install issue https://github.com/Homebrew/homebrew-php/issues/3586
Problem installing php70-mcrypt, php70-opcache, php70-xdebug on El Capitan https://github.com/Homebrew/homebrew-php/issues/3587
Add php70-zmq formula https://github.com/Homebrew/homebrew-php/pull/3474
Problem installing homebrew/php/php70-imagick https://github.com/Homebrew/homebrew-php/issues/3571
Install PHP70: Incompatible library version https://github.com/Homebrew/homebrew-php/issues/3444
brew install php70-redis https://github.com/Homebrew/homebrew-php/issues/2762
Allow --enable-redis-igbinary for php70-redis https://github.com/Homebrew/homebrew-php/pull/3473
Add head formula for php70-uploadprogress https://github.com/Homebrew/homebrew-php/pull/3178

This is on a fresh install of MacOS Sierra (actual release, not a beta) with a fresh install of Homebrew (updated). I have installed, ran and agreed to the Xcode licensing agreement.

I have no idea what these errors mean. How can I fix them?

Answer

Right I’ve figured it out. I’m posting the steps to successfully install the require components below in case anybody else stumbles upon this issue:

1). make sure Homebrew is up to date:

brew update

2). Fix the PHP 7 error by making sure Xcode is installed and then typing the following into the Terminal:

brew install apr apr-util
sudo mkdir -p /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.12.xctoolchain/usr/local/bin/
sudo ln -s /usr/local/opt/apr/bin/apr-1-config /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.12.xctoolchain/usr/local/bin/
sudo ln -s /usr/local/opt/apr-util/bin/apu-1-config /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.12.xctoolchain/usr/local/bin/

3). Run the following command (otherwise the PHP installation will complain about missing libz):

xcode-select --install

4). You can now install PHP 7 with Homebrew:

brew install homebrew/php/php70