title: Composer using the wrong PHP binary
body: <p>I am using MacOS Big Sur.</p>
  <p>I have a PHP 7.4 project with composer. Yesterday, after some failure with brew (that decided to update PHP when I asked to update git...), I had to reinstall my PHP7.4 (still using brew through brew install php@7.4).</p>
  <p>The issue is that right now, there is also a PHP binary preinstalled in MacOS, which is in PHP 7.3.</p>
  <p>For some weird reasons, Composer still uses that 7.3 PHP Binary instead of brew's 7.4. I have added 7.4 to my path and made an alias between PHP and the 7.4 binary. Also, I can't remember what I did to completely override the system binary when I first installed my project 6 months ago.</p>
  <p>The issue is that since my composer is set in 7.4 and it uses a 7.3, I get many errors.</p>
  <p>What can I do ?</p>
  <p>EDIT : <code>/usr/bin/env php</code> seems to point to the 7.3 one. Maybe an environment issue.</p>
  <p>Regards,</p>