Indy 10 for ArmV7

[KeesBl]

I try to use Indy 10 on Lazarus. I've installed Lazarus with fpcupdeluxe for cross compiling. My project is a minimal project:
program exportSmData;
{$mode objfpc}{$H+}
uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  Classes, SysUtils, idException, idHttp;
var cc: TidHttp;
begin
    cc:=TIdHttp.create(nil);
    cc.free;
end.

This compiles and links fine for targets Windows and Linux 64 bits. When I target Linux on Armv7 (for a Raspberry Pi) I get a link error:
....\cross\bin\arm-linux\arm-linux-gnueabihf-ld.exe: cannot find -lrt. A missing library?
I wonder whether it is possible to compile and link Indy 10 to Arm.
I've compiled and linked a few other programs with this setup to arm without problems.

Greetings,
Kees