mtrace: 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/bin/mtrace - from package: glibc-utils

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

On Debian possible default full paths are:

/usr/bin/mtrace - from package: libc-dev-bin

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

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