roff2text: 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/roff2text - from package: groff

You may install the required package with command apt-get install {package}
Error in other languages:
roff2text: bevel nie gevind nie
roff2text: comandă negăsită
roff2text: comando não encontrado
roff2text: commande introuvable
roff2text: command not found
roff2text: käsku ei ole
roff2text: không tìm thấy lệnh
roff2text: komanda nerasta
roff2text: Kommando nicht gefunden.
roff2text: kommandot finns inte
roff2text: komut yok
roff2text: nie znaleziono polecenia
roff2text: níor aimsíodh an t-ordú
roff2text: no se encontró la orden
roff2text: no s'ha trobat l'ordre
roff2text: opdracht niet gevonden
roff2text: parancs nem található
roff2text: perintah tidak ditemukan
roff2text: príkaz nenájdený
roff2text: příkaz nenalezen
roff2text: команда не найдена
roff2text: командата не е открита
roff2text: 命令找不到
roff2text: コマンドが見つかりません