selinuxexeccon: 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/sbin/selinuxexeccon - from package: selinux-utils

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