haml: 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/haml - from package: ruby-haml

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

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