changestool: 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/changestool - from package: reprepro

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