mh_install: 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/mh_install - from package: maven-repo-helper

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