[ios development] Addressing error 1

Error type : file '/applications/xcode.app/contents/developer/toolchains/xcodedefault.xctoolchain/usr/bin/../lib/clang/6.0/include/module.map' has been modified since the precompiled header '/users/sunoh/library/developer/xcode/deriveddata/modulecache/1m9n77pfkkv7z/uikit-2m4vyledi34v0.pcm' was built .....

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1. click the project on the left-hand side => below target => right click=> delete ***test***

2. Go to "Build Setting" => add -DNS_BLOCK_ASSERTIONS=1 for each row..

1. Click on your project (Usually on top of your in-Xcode-file-browser - blue Xcode icon).
2. Go to [Your project] under Targets.
3. Click on the Build Settings.
4. Search in the search box for: 'other c flag'. (On mine there were three options - disregard all options except the bold 'Other C Flags.')
5. Click on the third colom of 'Other C Flags' and enter: '-DNS_BLOCK_ASSERTIONS=1'