krb5-config.heimdal: 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/krb5-config.heimdal - from package: heimdal-multidev

You may install the required package with command apt-get install {package}
Error in other languages:
krb5-config.heimdal: bevel nie gevind nie
krb5-config.heimdal: comandă negăsită
krb5-config.heimdal: comando não encontrado
krb5-config.heimdal: commande introuvable
krb5-config.heimdal: command not found
krb5-config.heimdal: käsku ei ole
krb5-config.heimdal: không tìm thấy lệnh
krb5-config.heimdal: komanda nerasta
krb5-config.heimdal: Kommando nicht gefunden.
krb5-config.heimdal: kommandot finns inte
krb5-config.heimdal: komut yok
krb5-config.heimdal: nie znaleziono polecenia
krb5-config.heimdal: níor aimsíodh an t-ordú
krb5-config.heimdal: no se encontró la orden
krb5-config.heimdal: no s'ha trobat l'ordre
krb5-config.heimdal: opdracht niet gevonden
krb5-config.heimdal: parancs nem található
krb5-config.heimdal: perintah tidak ditemukan
krb5-config.heimdal: príkaz nenájdený
krb5-config.heimdal: příkaz nenalezen
krb5-config.heimdal: команда не найдена
krb5-config.heimdal: командата не е открита
krb5-config.heimdal: 命令找不到
krb5-config.heimdal: コマンドが見つかりません