So today I upgraded to Xcode 6.1 beta because I felt like having an afternoon of frustration. After upgrading my OS version, purging my old copy of Xcode and installing the newest version, I load up an existing project and:
[REDACTED]: no identity found
Command /usr/bin/codesign failed with exit code 1
After struggling for a bit, I found there is an easy, but completely unintuitive fix. Simply go into the Xcode Menu then Preferences
For your account, select View Details...
Hit the refresh icon.
If prompted to do so, let it download the missing profiles.
Oh yeah, and do a Build->Clean.
Headache hopefully gone.