gpg-sign-all: 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/gpg-sign-all - from package: kup-utils

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

On Debian possible default full paths are:

/usr/bin/gpg-sign-all - from package: kup-client

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

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