esmerge: 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/esmerge - from package: tstools

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

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