copy-cacerts.py: 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/copy-cacerts.py - from package: pyca

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

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