I am trying to set up my Symfony application on the Nitrous platform. It is recommended to have translations with help of the INTL pecl module, so I tried to install it (pecl install intl). But it seems that it's missing lib ICU headers. These are installed by default when you install php5-intl (through apt-get) but I does not have the right permissions. How can this issue be solved?
Have a look at the documentation chapter The Intl Component.
composer should automatically install symfony/intl: 1.0.* if the intl extension isn't available. Please note that you're limited to the en locale this way.
Check your phpinfo() output if the php-intl extension is available/enabled and if yes which ICU version it was compiled with.
If the extension isn't available/enabled and you have no way to install it ... you will need to use the fallback-version.