covered: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/bin/covered - from package: covered

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