pymvpa2: 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/pymvpa2 - from package: python-mvpa2

You may install the required package with command apt-get install {package}
Error in other languages:
pymvpa2: bevel nie gevind nie
pymvpa2: comandă negăsită
pymvpa2: comando não encontrado
pymvpa2: commande introuvable
pymvpa2: command not found
pymvpa2: käsku ei ole
pymvpa2: không tìm thấy lệnh
pymvpa2: komanda nerasta
pymvpa2: Kommando nicht gefunden.
pymvpa2: kommandot finns inte
pymvpa2: komut yok
pymvpa2: nie znaleziono polecenia
pymvpa2: níor aimsíodh an t-ordú
pymvpa2: no se encontró la orden
pymvpa2: no s'ha trobat l'ordre
pymvpa2: opdracht niet gevonden
pymvpa2: parancs nem található
pymvpa2: perintah tidak ditemukan
pymvpa2: príkaz nenájdený
pymvpa2: příkaz nenalezen
pymvpa2: команда не найдена
pymvpa2: командата не е открита
pymvpa2: 命令找不到
pymvpa2: コマンドが見つかりません