otfmerge: 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/otfmerge - from package: otf-trace

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

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