These options can be written with or without an equals-sign.
--add-opens module/package=target-module
--add-opens=module/package=target-module
Only the version with 2 equals-signs seems to work when specified via included VM-options file.
Both syntaxes are supported. However, in the syntax
--add-opens module/package=target-module
there are two separate arguments. You cannot have both arguments on a single line in the .vmoptions file. They each have to be on a separate line:
--add-opens
module/package=target-module