update your php-intl extension, that’s where the icu error comes from!
sudo aptitude install php5-intl // i.e. ubuntu
brew install icu4c // osx
check the extension is enabled and properly configured in php.ini aswell.
( hint: php-cli sometimes uses a different php.ini )
php.ini
extension=intl.so ; *nix
extension=php_intl.dll ; windows
[intl]
intl.default_locale = en_utf8
intl.error_level = E_WARNING
check your phpinfo() AND php -m from your terminal if the extension has been succesfully enabled.
Check your current intl versions from php with:
Intl::getIcuVersion();
Intl::getIcuDataVersion();
attention: not needed anymore ( symfony 2.3 has meanwhile been released )
add the minimum stability flag @dev or @rc to your dependency like this please:
composer create-project symfony/framework-standard-edition mynewerproject/ 2.3.*@dev
The default stability in composer is stable which symfony 2.3 branch is not currently ( it’s @rc ). Read more an stability flags here.