warning: Unable to read symbols

When I try to run my app in iOS 4.2.1, I am getting following warning messages;

[Switching to thread 11523]
[Switching to thread 11523]
`/xcode iOS/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/usr/lib/dyld' has changed; re-reading symbols.
`/xcode iOS/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/usr/lib/dyld' has changed; re-reading symbols.
continue
`/xcode 开发者_StackOverflowiOS/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/usr/lib/dyld' has changed; re-reading symbols.
`/xcode iOS/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/usr/lib/dyld' has changed; re-reading symbols.
warning: Unable to read symbols for /xcode iOS/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/usr/lib/info/dns.so (file not found).

I don't know what is happening here.

Is there any issues, when we get this kind of warning messages ?

I'm sure this will solve your problem: UUID mismatch detected with the loaded library

• Johannes

The problem is that Xcode and the debugger expect iOS 4.2, but your device runs iOS 4.2.1.

What you can do to avoid this error; Let Xcode gather the needed symbols from your device (you may have to delete previous ones). After this, it will work without any problem.

I've been running into this same issue lately when compiling an app in Xcode 4.2, so I searched for this same issue in the apple developer forums, and I found many threads specifically about this dns.so warning, and in many of these threads, Apple engineers replied and said it's ok to ignore this warning when it involves dns.so. One of them stated it would not even be used on iOS, so it can be ignored.