gtk2hsC2hs: 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/gtk2hsC2hs - from package: gtk2hs-buildtools

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

On Debian possible default full paths are:

/usr/bin/gtk2hsC2hs - from package: gtk2hs-buildtools

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

Error in other languages:
gtk2hsC2hs: bevel nie gevind nie
gtk2hsC2hs: comandă negăsită
gtk2hsC2hs: comando não encontrado
gtk2hsC2hs: commande introuvable
gtk2hsC2hs: command not found
gtk2hsC2hs: käsku ei ole
gtk2hsC2hs: không tìm thấy lệnh
gtk2hsC2hs: komanda nerasta
gtk2hsC2hs: Kommando nicht gefunden.
gtk2hsC2hs: kommandot finns inte
gtk2hsC2hs: komut yok
gtk2hsC2hs: nie znaleziono polecenia
gtk2hsC2hs: níor aimsíodh an t-ordú
gtk2hsC2hs: no se encontró la orden
gtk2hsC2hs: no s'ha trobat l'ordre
gtk2hsC2hs: opdracht niet gevonden
gtk2hsC2hs: parancs nem található
gtk2hsC2hs: perintah tidak ditemukan
gtk2hsC2hs: príkaz nenájdený
gtk2hsC2hs: příkaz nenalezen
gtk2hsC2hs: команда не найдена
gtk2hsC2hs: командата не е открита
gtk2hsC2hs: 命令找不到
gtk2hsC2hs: コマンドが見つかりません