aclcheck.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/plugins/scmcvs/bin/aclcheck.php - from package: fusionforge-plugin-scmcvs

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

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