qmlplugindump: command not found

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 CentOS possible default full paths are:

/usr/lib64/qt5/bin/qmlplugindump - from package: qt5-qtdeclarative-devel
/usr/lib/qt5/bin/qmlplugindump - from package: qt5-qtdeclarative-devel

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/lib/x86_64-linux-gnu/qt4/bin/qmlplugindump - from package: qt4-dev-tools
/usr/bin/qmlplugindump - from package: qtchooser
/usr/lib/x86_64-linux-gnu/qt5/bin/qmlplugindump - from package: qtdeclarative5-dev-tools

You may install the required package with command apt-get install {package}

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