https://manual.calibre-ebook.com/gen...n/calibre.html
use the --with_library option
then
use the Create/switch:use existing option to set the same path. that make it current.
BUT something is odd
When Calibre was installed, it creates Calibre Library in the default location.
If Calibre cant find the
Current Library, it usually either uses this or recreates it. It has 1 book. Then you just switch to the one you want.