gnome-photos: 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/gnome-photos - from package: gnome-photos

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

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