lambdabot: 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/lambdabot - from package: lambdabot

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

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