asterisk-tests-run: 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/asterisk-tests-run - from package: asterisk-testsuite

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

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