$load x=x.l not allowed (GAMS bug)

When a variable x is stored in a GDX file we can read it as a parameter as follows:

parameter x(k,i,t);
execute_load 'merged.gdx',x=x.l;

Unfortunately at compile time we don't have the same facility:

parameter x(k,i,t);
$gdxin merged.gdx
$load x=x.l

yields

5923  parameter x(k,i,t);
GDXIN   C:\projects\china\input\merged.gdx
5925  $load x=x.l
****            $490
**** LINE     19 INPUT       C:\projects\china\input\report.gms
**** 490  Cannot load/unload this suffix