Drush does not work invoking the local Drush
This Drush issue has been fixed in the recent version (8.1.5 and above) by refactoring how the code was using Phar class.

Here are updated steps how to install Drush using phar (as per install.md):

# Download latest stable release using the code below or browse to github.com/drush-ops/drush/releases.
php -r "readfile('http://files.drush.org/drush.phar');" &gt; drush
# Or use our upcoming release: php -r "readfile('http://files.drush.org/drush-unstable.phar');" &gt; drush

# Test your install.
php drush core-status

# Make `drush` executable as a command from anywhere. Destination can be anywhere on $PATH.
chmod +x drush
sudo mv drush /usr/local/bin

# Optional. Enrich the bash startup file with completion and aliases.
drush init


Or by the following one-liner:

sudo install &lt;(curl http://files.drush.org/drush.phar) /usr/local/bin/drush