Remove old issues in Xcode

I have one trouble with Xcode - sometimes errors and warnings in Issue Navigator persists even when they are fixed. So I have no warnings/errors in log. I can run my project, but in status window and in Issues Navigator I see errors.

I can filter them out using "Show only issues from the latest build", but this is not what I want - I want to see all actual warnings.

Do you know how to keep issues up to date?

How do I delete a swift project in Xcode?

With Xcode closed, locate that project folder in the Finder, move it to the trash, then empty the trash.

How do I delete the build folder in IOS?

To clean the build folder you can use the shortcut Command+Option+Shift+K or Menu Bar → Product → Hold Option Key → Clean build Folder .

Which one of the following options permanently deletes a file in Xcode?

You can delete it in finder or in Xcode by pressing Command-Option-Shift-K before delete the project itself.

This is still happening in Xcode 9.4.1. The fix is the same as the previous answer for Xcode 6, but the steps are slightly different:

Close the project in Xcode
Go to Preferences... > Locations
Click the arrow next to the Derived Data path, which will open the folder in Finder, e.g. /Users/xxx/Library/Developer/Xcode/DerivedData
Delete the subfolder relevant to the project you're having trouble with
Reopen the project