ocamldebug: 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/ocamldebug - from package: ocaml

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

On Debian possible default full paths are:

/usr/bin/ocamldebug - from package: ocaml-nox

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

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