sprockets: 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/sprockets - from package: ruby-sprockets

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