nosetests-2.7: 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/nosetests-2.7 - from package: python-nose

You may install the required package with command apt-get install {package}
Error in other languages:
nosetests-2.7: bevel nie gevind nie
nosetests-2.7: comandă negăsită
nosetests-2.7: comando não encontrado
nosetests-2.7: commande introuvable
nosetests-2.7: command not found
nosetests-2.7: käsku ei ole
nosetests-2.7: không tìm thấy lệnh
nosetests-2.7: komanda nerasta
nosetests-2.7: Kommando nicht gefunden.
nosetests-2.7: kommandot finns inte
nosetests-2.7: komut yok
nosetests-2.7: nie znaleziono polecenia
nosetests-2.7: níor aimsíodh an t-ordú
nosetests-2.7: no se encontró la orden
nosetests-2.7: no s'ha trobat l'ordre
nosetests-2.7: opdracht niet gevonden
nosetests-2.7: parancs nem található
nosetests-2.7: perintah tidak ditemukan
nosetests-2.7: príkaz nenájdený
nosetests-2.7: příkaz nenalezen
nosetests-2.7: команда не найдена
nosetests-2.7: командата не е открита
nosetests-2.7: 命令找不到
nosetests-2.7: コマンドが見つかりません