widemargin: 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/widemargin - from package: widemargin

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

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