gnustep-config: command not found

Have You tried accessing the binary with the full path?

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/gnustep-config - from package: gnustep-make

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

On Debian possible default full paths are:

/usr/bin/gnustep-config - from package: gnustep-make

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