spring: 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/spring - from package: ruby-spring

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