protoc-gen-beefcake: 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/protoc-gen-beefcake - from package: ruby-beefcake

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

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