cdcover: 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 Debian possible default full paths are:

/usr/bin/cdcover - from package: cdcover

You may install the required package with command apt-get install {package}

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