stellar: 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/stellar - from package: seqan-apps
/usr/lib/seqan/bin/stellar - from package: seqan-apps

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

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