weston-terminal: 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/weston-terminal - from package: weston

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