libobjc-4.dll: 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 CentOS possible default full paths are:

/usr/i686-w64-mingw32/sys-root/mingw/bin/libobjc-4.dll - from package: mingw32-gcc-objc
/usr/x86_64-w64-mingw32/sys-root/mingw/bin/libobjc-4.dll - from package: mingw64-gcc-objc

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

Error in other languages:
libobjc-4.dll: bevel nie gevind nie
libobjc-4.dll: comandă negăsită
libobjc-4.dll: comando não encontrado
libobjc-4.dll: commande introuvable
libobjc-4.dll: command not found
libobjc-4.dll: käsku ei ole
libobjc-4.dll: không tìm thấy lệnh
libobjc-4.dll: komanda nerasta
libobjc-4.dll: Kommando nicht gefunden.
libobjc-4.dll: kommandot finns inte
libobjc-4.dll: komut yok
libobjc-4.dll: nie znaleziono polecenia
libobjc-4.dll: níor aimsíodh an t-ordú
libobjc-4.dll: no se encontró la orden
libobjc-4.dll: no s'ha trobat l'ordre
libobjc-4.dll: opdracht niet gevonden
libobjc-4.dll: parancs nem található
libobjc-4.dll: perintah tidak ditemukan
libobjc-4.dll: príkaz nenájdený
libobjc-4.dll: příkaz nenalezen
libobjc-4.dll: команда не найдена
libobjc-4.dll: командата не е открита
libobjc-4.dll: 命令找不到
libobjc-4.dll: コマンドが見つかりません