Recently, We developed a Custom Resolver which deletes the dependent pages from the package, while publishing a component dynamically.
The Custom Resolver actually overrides the default OOB resolver, more details could be found here.
Basically resolving is a process in which publisher identifies the dependent items, which are supposed to publish with the published item. It is a part of overall publishing process and happens before rendering sub-process.
Since we are overriding the resolving process, it's obvious to deploy the Custom Resolver on the server where publisher runs.
In our case, we had a separate publishing server, so we deployed the custom resolver to the publisher server. And it started working as expected by not including the dependent pages while publishing the components.
But then we noticed one issue, On publishing a component, in the publishing dialog on clicking “Show Items to Publish” button the dependent pages were still showing.
And it was confusing content editors that dependent pages are being published and resolver is not working. Though it was working actually and it's just the dependent pages were listed in the publish dialog.
The issue occurred because the “Show Items to Publish” button uses resolver on CMS server not on Publisher server. And since we didn't deploy our custom resolver to CMS server the default resolver was running there.
So to fix the issue, we needed to deploy our custom resolver on CMS server as well so that it overrides the default behavior of the resolver.
And once we deployed the custom resolver to CMS server, the issue was resolved.