I have tried to run this command line with the same gds file present in my tcl script
calibredrv -a layout filemerge -in file1.gds -in file2.gds.gz -in file3.gds.gz -out test2.gds
and the layout on final test2.gds file, is NOT empty.
I have also removed the precision setting on my script, but using this one, I cannot generate the layout I need
Thanks and regards
Luciano