fc-pattern: 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/fc-pattern - from package: fontconfig

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