yesod: command not found

Have You tried accessing the binary with the full path?

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/yesod - from package: yesod

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