gpgsigs: 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/gpgsigs - from package: signing-party

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

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