gtags-cscope: 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-cscope - from package: global

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

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