nose2: 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/nose2 - from package: python-nose2

You may install the required package with command apt-get install {package}
Error in other languages:
nose2: bevel nie gevind nie
nose2: comandă negăsită
nose2: comando não encontrado
nose2: commande introuvable
nose2: command not found
nose2: käsku ei ole
nose2: không tìm thấy lệnh
nose2: komanda nerasta
nose2: Kommando nicht gefunden.
nose2: kommandot finns inte
nose2: komut yok
nose2: nie znaleziono polecenia
nose2: níor aimsíodh an t-ordú
nose2: no se encontró la orden
nose2: no s'ha trobat l'ordre
nose2: opdracht niet gevonden
nose2: parancs nem található
nose2: perintah tidak ditemukan
nose2: príkaz nenájdený
nose2: příkaz nenalezen
nose2: команда не найдена
nose2: командата не е открита
nose2: 命令找不到
nose2: コマンドが見つかりません