phpcs --standard=PSR1,PSR2,PSR12 pharstub.php

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FOUND 1 ERROR AFFECTING 1 LINE
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 7 | ERROR | [x] PHP keywords must be lowercase; expected
   |       |     "__halt_compiler" but found "__HALT_COMPILER"
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PHPCBF CAN FIX THE 1 MARKED SNIFF VIOLATIONS AUTOMATICALLY
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The problem is that despite what the documentation would suggest, this function must be upper case for include phar:///path/archive.phar/public/index.php to work from the phar stub. Seriously, I cannot make this stuff up:

PHP message: PHP Warning: include(): Failed opening 'public/index.php' for inclusion (include_path='phar:///tmp/archive.phar:.:/usr/share/php7:/usr/share/php') in /tmp/archive.phar on line 6"

Switching __halt_compiler() to __HALT_COMPILER() resolves this issue.

See halt-compiler vs phar.stub