This error appears after one of "pod update" calls.
I've already tried:
I'm sure that I'm opening Workspace instead of project (there's no errors for SwiftyJson).
Pods framework is added to "Link with":
Error message:
Files listing:
$ ls Pods/SDWebImage/
LICENSE README.md SDWebImage
XCode version is 7.3.1, OS X 10.11.
So, the problem was solved by calling
pod deintegrate
removing xcworkspace and reinstalling pods.