coverage.php: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/share/pear/symfony/plugins/sfDoctrinePlugin/test/bin/coverage.php - from package: php-symfony-symfony

You may install the required package with command yum install {package}

Error in other languages:
coverage.php: bevel nie gevind nie
coverage.php: comandă negăsită
coverage.php: comando não encontrado
coverage.php: commande introuvable
coverage.php: command not found
coverage.php: käsku ei ole
coverage.php: không tìm thấy lệnh
coverage.php: komanda nerasta
coverage.php: Kommando nicht gefunden.
coverage.php: kommandot finns inte
coverage.php: komut yok
coverage.php: nie znaleziono polecenia
coverage.php: níor aimsíodh an t-ordú
coverage.php: no se encontró la orden
coverage.php: no s'ha trobat l'ordre
coverage.php: opdracht niet gevonden
coverage.php: parancs nem található
coverage.php: perintah tidak ditemukan
coverage.php: príkaz nenájdený
coverage.php: příkaz nenalezen
coverage.php: команда не найдена
coverage.php: командата не е открита
coverage.php: 命令找不到
coverage.php: コマンドが見つかりません