ocamlyacc: 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/ocamlyacc - from package: ocaml

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

On Debian possible default full paths are:

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

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

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