Thank you for using PHPStan!
With the release of PHPStan 0.12, the primary Composer package used by most users,
phpstan/phpstan, has switched to a PHAR file. It works the same way as phpstan-shim.
The need for a separate PHAR distribution has ceased.
Package phpstan/phpstan-shim is no longer needed.
You should upgrade to phpstan/phpstan 0.12 with the following steps:
1) In your composer.json, rewrite line with "phpstan/phpstan-shim"
to "phpstan/phpstan": "^0.12".
2) Delete your composer.lock.
3) Delete vendor/phpstan directory.
4) Delete vendor/bin/phpstan and vendor/bin/phpstan.phar.
5) Run composer install.
If you have any problem upgrading, don't hesitate to describe your issue at: https://github.com/phpstan/phpstan/issues/new/choose