gdk-pixbuf-query-loaders: 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/gdk-pixbuf-query-loaders - from package: libgdk-pixbuf2.0-dev

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