deweb: 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/deweb - from package: chktex

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