gtk2hsTypeGen: 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/gtk2hsTypeGen - from package: gtk2hs-buildtools

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

On Debian possible default full paths are:

/usr/bin/gtk2hsTypeGen - from package: gtk2hs-buildtools

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

Error in other languages:
gtk2hsTypeGen: bevel nie gevind nie
gtk2hsTypeGen: comandă negăsită
gtk2hsTypeGen: comando não encontrado
gtk2hsTypeGen: commande introuvable
gtk2hsTypeGen: command not found
gtk2hsTypeGen: käsku ei ole
gtk2hsTypeGen: không tìm thấy lệnh
gtk2hsTypeGen: komanda nerasta
gtk2hsTypeGen: Kommando nicht gefunden.
gtk2hsTypeGen: kommandot finns inte
gtk2hsTypeGen: komut yok
gtk2hsTypeGen: nie znaleziono polecenia
gtk2hsTypeGen: níor aimsíodh an t-ordú
gtk2hsTypeGen: no se encontró la orden
gtk2hsTypeGen: no s'ha trobat l'ordre
gtk2hsTypeGen: opdracht niet gevonden
gtk2hsTypeGen: parancs nem található
gtk2hsTypeGen: perintah tidak ditemukan
gtk2hsTypeGen: príkaz nenájdený
gtk2hsTypeGen: příkaz nenalezen
gtk2hsTypeGen: команда не найдена
gtk2hsTypeGen: командата не е открита
gtk2hsTypeGen: 命令找不到
gtk2hsTypeGen: コマンドが見つかりません