gen_keymap: 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/gen_keymap - from package: keymapper

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