gtags-parser: 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 Debian possible default full paths are:

/usr/bin/gtags-parser - from package: global

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

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