dustmasker: 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/dustmasker - from package: ncbi-blast+

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