stretcher: 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

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/stretcher - from package: emboss

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