gbp-pq: 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/gbp-pq - from package: git-buildpackage

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

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