Error installing php 71 with homebrew on my mac - php

Question

I have been developing with Vallet for some time now. Today i wanted to update laravel 5.4 to 5.5. Before doing so i run composer global update. Causing Vallet to stop working.
Fist i tried to do the following:
cd ~/.composer/
sudo chown -R $(whoami) vendor
source: https://laracasts.com/discuss/channels/general-discussion/getting-valet-not-found-error
I did not solve the issue. Then i decided to reinstall Vallet. Hereby i did the following:
I followed this: https://github.com/laravel/valet/issues/321
Stop and uninstall services
sudo brew services stop php71 dnsmasq nginx
brew uninstall php71 dnsmasq nginx
Remove related config files and valet home folder
sudo rm -r /usr/local/etc/php /usr/local/etc/nginx /usr/local/etc/dnsmasq.conf
sudo rm -r ~/.valet /var/root/.valet
Install services i tried this:
brew install php71
$ brew tap homebrew/php
$ brew install php71
brew install homebrew/php/php71
All gave the following error:
MacBook-Pro:~ mblivier$ brew install homebrew/php/php71
==> Installing php71 from homebrew/php Error: The following formula: php71
cannot be installed as a binary package and must be built from source.
Install the Command Line Tools:xcode-select --install
I new in this and don't know how to solve this. Any suggestions how to install php and go further with reinstalling Vallet?
homebrew is installed and working

Answer 1

You need xcode to build php, so first run:
xcode-select --install
to install xcode and later you can brew install php71

Answer 2

This is answer for your comment, I can't post as comment, need to post because is length limited.
There is one of two things going on here, either you didn't install PHP, or PHP is installed and not currently in any of system aware paths. First I would try to find PHP and make sure it exists:
$ find / -name php -type f
You should see something like:
/path/to/your/php/bin/php
If PHP binary does exist, check your path:
$ echo $PATH
If it does not exist, recompile php.
If PHP exists on your system, make sure the path to the /bin/php file is included. You can edit your ~/.bash_profile and add the custom path like this:
PATH=$PATH:/path/to/your/php/bin/
....
export PATH
Then save and reload the file to ensure your current session has access to new path changes:
$ source ~/.bash_profile
With any luck you can now do a php -v and see the version response.