xcode - Swift Sdtlib tool error: Task failed with exit code 1

Question

So randomly after several hours of work this morning on my app, Xcode just stopped letting me test my app on my iPhone. But I can still test it in the simulator.

Now, when I build a project (note: ANY project, even blank single view project that was just created), I get the following error;

Codesigning /Users/name/Library/Developer/Xcode/DerivedData/testProject-brzcahttttlkoqeczajhqslodkkn/Build/Products/Debug-iphoneos/testProject.app/Frameworks/libswiftCore.dylib /usr/bin/codesign '--force' '--sign' '64F8B22715267CC0910110D9C97A2567591C0235' '--verbose' '/Users/name/Library/Developer/Xcode/DerivedData/testProject-brzcahttttlkoqeczajhqslodkkn/Build/Products/Debug-iphoneos/testProject.app/Frameworks/libswiftCore.dylib' 

SecKey API returned: -25304, (null)/Users/name/Library/Developer/Xcode/DerivedData/testProject-brzcahttttlkoqeczajhqslodkkn/Build/Products/Debug-iphoneos/testProject.app/Frameworks/libswiftCore.dylib: unknown error -1=ffffffffffffffff error: Task failed with exit 1 signal 0 {    /usr/bin/codesign '--force' '--sign' '64F8B22715267CC0910110D9C97A2567591C0235' '--verbose' '/Users/name/Library/Developer/Xcode/DerivedData/testProject-brzcahttttlkoqeczajhqslodkkn/Build/Products/Debug-iphoneos/testProject.app/Frameworks/libswiftCore.dylib'

I'm running Xcode 8.2 on macOS Sierra 10.12.12, testing on an iPhone 6s with iOS 10.1.1.

Note: I have reinstalled Xcode after fully removing it from my machine, as well deleting and recreating all my provisioning profiles for all hardware.

Answer 1

Ok so I solved this, don't know if it's the right way or not.

Moved my iOS developer certificate from local to system using Key Chain.

Steps:

1. Close Xcode.
2. Open Key Chain.
3. Find the iOS Developer cert in Local.
4. Drag and drop the cert from Local to the System tab.
5. Enter admin password when prompted.
6. Start Xcode and build project for your device.