pwqcheck: 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/pwqcheck - from package: passwdqc

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