sync_unix_groups.php: 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/share/gforge/bin/sync_unix_groups.php - from package: gforge-db-postgresql

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

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