jtreg: 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/jtreg - from package: jtreg

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

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