uwsgi_luajit: 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/uwsgi_luajit - from package: uwsgi-plugin-luajit

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