pi@raspberrypi:~/pocketmine $ ./start.sh
Couldn't find a working PHP 7 binary, please use the installer.
pi@raspberrypi:~/pocketmine $ php -v
PHP 7.0.12-1 (cli) ( NTS )
Copyright (c) 1997-2016 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies
with Zend OPcache v7.0.12-1, Copyright (c) 1999-2016, by Zend Technologies
I don't know what the problem is.
I ran the command given by the "get pocketmine" section of the website
I noticed the same error, when I looked in the start.sh script I saw it was calling PHP7 but in fact it downloads PHP5. I updated the script so it reflected what it did.
run this perl -i -pe 's/php7/php5/g' start.sh
this will replace php7 with php5. this should get you started.
Project has moved -> check README.md