camlp4boot: 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

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/camlp4boot - from package: ocaml-camlp4-devel

You may install the required package with command yum install {package}
Error in other languages:
camlp4boot: bevel nie gevind nie
camlp4boot: comandă negăsită
camlp4boot: comando não encontrado
camlp4boot: commande introuvable
camlp4boot: command not found
camlp4boot: käsku ei ole
camlp4boot: không tìm thấy lệnh
camlp4boot: komanda nerasta
camlp4boot: Kommando nicht gefunden.
camlp4boot: kommandot finns inte
camlp4boot: komut yok
camlp4boot: nie znaleziono polecenia
camlp4boot: níor aimsíodh an t-ordú
camlp4boot: no se encontró la orden
camlp4boot: no s'ha trobat l'ordre
camlp4boot: opdracht niet gevonden
camlp4boot: parancs nem található
camlp4boot: perintah tidak ditemukan
camlp4boot: príkaz nenájdený
camlp4boot: příkaz nenalezen
camlp4boot: команда не найдена
camlp4boot: командата не е открита
camlp4boot: 命令找不到
camlp4boot: コマンドが見つかりません