doxyindexer: 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/doxyindexer - from package: doxygen

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