Anyone else has this issue? What can be done to fix that?
I had the same problem. I looked in my keychain and there were over 500 copies one of my certificates, and a few others were duplicated a few hundred times. I removed all the duplicates and kept just one of each, and my code signing time went from 30 seconds per framework down to about 1 second per. I don't know how the certificates were duplicated, but the timing of the issue suggests it was due to updating Sierra to 10.12.1.
For those who don't have many certificates and are still experiencing this issue, I fixed it by following the advice at the end of the stackoverflow link:
Edit ~/Library/Preferences/com.apple.security.plist and make sure that there is only one entry. I had 6 or 7 duplicate paths for the same login keychain. Removing the duplicate entries fixed the issue for me!
You need more points. This helped me greatly. 2300+ duplicate certificates. Removing them took my build time from 2hours to 21 minutes.
I updated to Sierra (10.12.2) a few days ago and still looking for answers for this...
I don't have multiple certificates, and there is no com.apple.security.plist file in my Preferences folder.
There are 3 other files:
com.apple.security.cloudkeychainproxy3.keysToRegister.plist
com.apple.security.KCN.plist
com.apple.security.revocation.plist
Checking inside those I didn't find something useful or seemingly relevant.
Any ideas?
Updating to XCode 8.3 has fixed this problem. 🙂