rivet-buildplugin: 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/rivet-buildplugin - from package: rivet-plugins-dev

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