Xcode 6 Beta Toolchain Error

Question

I am trying to compile an some code of an app I am currently working on and run it on an iPhone, but every time I run it, the build fails and this is the error:

/Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-stdlib-tool failed with exit code 1

It was working perfectly two days ago, I have no idea how to fix it.

Answer 1

Refreshing my Accounts under Xcode > Preferences… > Accounts > View Details… did the trick for me.

Answer 2

I experienced this exact issue and spent some time trying to figure out what the cause was. For some reason, it worked on my physical iOS device but refused to run in the iOS Simulator and that was the error presented.

In my case, I recently added a target so I could create a custom keyboard and before that it did run without issue in the simulator. So I decided to delete the new target, recreate it, then revoke my iOS developer certificate, and then delete my certificates and everything in Keychain (there were many duplicates). I recreated them, then created a new App ID that uses the exact same identifier as the Bundle Identifier for my keyboard target (found in the General section after selecting the keyboard target), then I created a provisioning profile for that App ID. Then I went into the Xcode Preferences and refreshed, and it automatically "renewed" my now invalid provisioning profiles. Finally, I went through the project, main app target, and the keyboard target and set up the Code Signing sections. Hit Command R and like magic, Build Succeeded.

It was kind of a pain, but it came down to some issue with the code signing and provision profiles. Hopefully you will be able to resolve your problem with this information.