hy2: 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/hy2 - from package: python-hy

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

Error in other languages:
hy2: bevel nie gevind nie
hy2: comandă negăsită
hy2: comando não encontrado
hy2: commande introuvable
hy2: command not found
hy2: käsku ei ole
hy2: không tìm thấy lệnh
hy2: komanda nerasta
hy2: Kommando nicht gefunden.
hy2: kommandot finns inte
hy2: komut yok
hy2: nie znaleziono polecenia
hy2: níor aimsíodh an t-ordú
hy2: no se encontró la orden
hy2: no s'ha trobat l'ordre
hy2: opdracht niet gevonden
hy2: parancs nem található
hy2: perintah tidak ditemukan
hy2: príkaz nenájdený
hy2: příkaz nenalezen
hy2: команда не найдена
hy2: командата не е открита
hy2: 命令找不到
hy2: コマンドが見つかりません