mixbench: 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/mixbench - from package: golang-gogoprotobuf-dev

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