dgscat-long: 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/dgscat-long - from package: ptscotch

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