GraphicsMagickWand-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/GraphicsMagickWand-config - from package: GraphicsMagick-devel

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

On Debian possible default full paths are:

/usr/bin/GraphicsMagickWand-config - from package: libgraphicsmagick1-dev

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