libIDL-config-2: 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/bin/libIDL-config-2 - from package: libIDL-devel

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

On Debian possible default full paths are:

/usr/bin/libIDL-config-2 - from package: libidl-dev

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

Error in other languages:
libIDL-config-2: bevel nie gevind nie
libIDL-config-2: comandă negăsită
libIDL-config-2: comando não encontrado
libIDL-config-2: commande introuvable
libIDL-config-2: command not found
libIDL-config-2: käsku ei ole
libIDL-config-2: không tìm thấy lệnh
libIDL-config-2: komanda nerasta
libIDL-config-2: Kommando nicht gefunden.
libIDL-config-2: kommandot finns inte
libIDL-config-2: komut yok
libIDL-config-2: nie znaleziono polecenia
libIDL-config-2: níor aimsíodh an t-ordú
libIDL-config-2: no se encontró la orden
libIDL-config-2: no s'ha trobat l'ordre
libIDL-config-2: opdracht niet gevonden
libIDL-config-2: parancs nem található
libIDL-config-2: perintah tidak ditemukan
libIDL-config-2: príkaz nenájdený
libIDL-config-2: příkaz nenalezen
libIDL-config-2: команда не найдена
libIDL-config-2: командата не е открита
libIDL-config-2: 命令找不到
libIDL-config-2: コマンドが見つかりません