starpu_workers_activity: 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/starpu_workers_activity - from package: starpu-tools

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