roff2pdf: 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/roff2pdf - from package: groff

You may install the required package with command apt-get install {package}
Error in other languages:
roff2pdf: bevel nie gevind nie
roff2pdf: comandă negăsită
roff2pdf: comando não encontrado
roff2pdf: commande introuvable
roff2pdf: command not found
roff2pdf: käsku ei ole
roff2pdf: không tìm thấy lệnh
roff2pdf: komanda nerasta
roff2pdf: Kommando nicht gefunden.
roff2pdf: kommandot finns inte
roff2pdf: komut yok
roff2pdf: nie znaleziono polecenia
roff2pdf: níor aimsíodh an t-ordú
roff2pdf: no se encontró la orden
roff2pdf: no s'ha trobat l'ordre
roff2pdf: opdracht niet gevonden
roff2pdf: parancs nem található
roff2pdf: perintah tidak ditemukan
roff2pdf: príkaz nenájdený
roff2pdf: příkaz nenalezen
roff2pdf: команда не найдена
roff2pdf: командата не е открита
roff2pdf: 命令找不到
roff2pdf: コマンドが見つかりません