cloog-isl: 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/cloog-isl - from package: cloog-isl

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

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