gphotofs: 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/gphotofs - from package: gphotofs

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

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