pkgconf: 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/pkgconf - from package: pkgconf

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

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