ghc-events: 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 Debian possible default full paths are:

/usr/bin/ghc-events - from package: libghc-ghc-events-dev

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

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