buildhash: 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
/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 Debian possible default full paths are:

/usr/bin/buildhash - from package: ispell

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