stag-handle: 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/stag-handle - from package: libdata-stag-perl

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