See this link first, gitlab
I filed a issue for a add-on for request limit the add-on’s compatible system, and the author replied that the add-on also support for Solaris. So for now, there is no way to enable support for Solaris but exclude some particular OSs in compatible list.
Firefox doesn’t has a official build for Solaris OS, there is a Oracle built one. May be there is a few more Firefox build for other OS, which are not listed in the selection. AMO submitting page provided a limited selection, it can’t cover with all the case that the publisher want. Maybe AMO should add more options, such as customizing platform name, or offer a blacklist if AMO can’t list all OS.
Submitting an add-on
We’re moving in the opposite direction, actually. The WebExtensions API is generally cross-platform, so we don’t want to maintain the complexity of platform compatibility. If an extension only works on specific platforms, they can be self-distributed on sites that have the appropriate warnings / browser checks. AMO is meant for broad distribution to Firefox users.
I have installed an extension before, it’s a legacy add-on. I installed that add-on on Linux and then Firefox sync the extensions list to other platform, it will be automatically disabled on Windows. I don’t know which part determine the publish behavior I said above, AMO or some bit-settings on add-on’s packages.
The WebExtensions is designed for cross-platform, but some specific extensions are not. If WE is ongoing the way to support all platforms, it’s more reasonable to change the current used “Including List” to a “Excluding List”.
Legacy add-ons could declare platform compatibility in the manifest. WebExtension add-ons cannot. They should be able to detect the platform in code and fail gracefully, though.