gss-client: 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 CentOS possible default full paths are:

/usr/bin/gss-client - from package: krb5-devel

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/gss-client - from package: krb5-gss-samples

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

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