ginac-excompiler: 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/ginac-excompiler - from package: ginac-tools

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

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