PHP5.6 compatibility

[sarigue]

PHP 5.6 is an older version of PHP, but it's still sometimes used...
Also, a PHP 5.6-compatible version of the PSR interfaces can be useful.
I propose an "old-version" new branch with the tag 0.9

[Jean85]

I'm sorry but this is a complete no-go. As an organization PHP-FIG shouldn't endorse using such an old version of PHP, especially by altering an already published standard that required that version from its inception.

You're obviously free to run your own fork or publish another package with a replace keyword, so that it makes it usable for your purpose; but I fear you'll have issue finding implementing code that do not have the same issue\constraint.

[shadowhand]

PHP 5.6 has been unsupported for >6 years at the time this issue was created. https://php.net/eol