stap-merge: 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/stap-merge - from package: systemtap-runtime

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

On Debian possible default full paths are:

/usr/bin/stap-merge - from package: systemtap-runtime

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

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