title: clang: error: no such file or directory: '/Users/waterskiingmithrill/Development/iPhone/Event/Event_Prefix.pch'
body: <p>I've messed up my iPhone project.  I ran <code>svn update</code>, having fiddled with the repository months ago.  Many changes since, make recovering from an old point nearly impossible.</p>
  
  <p>When I attempt to build the project now I get:</p>
  
  <pre><code>ProcessPCH /Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/PrecompiledHeaders/Event_Prefix-brpgiiwwokyynuheloumlvxlmurs/Event_Prefix.pch.pth Event_Prefix.pch normal i386 objective-c com.apple.compilers.llvm.clang.1_0.compiler
  cd /Users/waterskiingmithrill/Development/iPhone/Event
  setenv LANG en_US.US-ASCII
  setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -x objective-c-header -arch i386 -fmessage-length=0 -std=c99 -Wno-trigraphs -fpascal-strings -O0 -Wno-missing-field-initializers -Wno-missing-prototypes -Wreturn-type -Wno-implicit-atomic-properties -Wformat -Wno-missing-braces -Wparentheses -Wswitch -Wno-unused-function -Wno-unused-label -Wno-unused-parameter -Wunused-variable -Wunused-value -Wno-uninitialized -Wno-unknown-pragmas -Wno-shadow -Wno-four-char-constants -Wno-sign-compare -Wno-shorten-64-to-32 -Wpointer-sign -Wno-newline-eof -Wno-selector -Wno-strict-selector-match -Wno-undeclared-selector -Wno-deprecated-implementations -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk -fexceptions -fasm-blocks -Wprotocol -Wdeprecated-declarations -mmacosx-version-min=10.6 -g -fvisibility=hidden -Wno-conversion -Wno-sign-conversion -fobjc-abi-version=2 -fobjc-legacy-dispatch "-DIBOutlet=__attribute__((iboutlet))" "-DIBOutletCollection(ClassName)=__attribute__((iboutletcollection(ClassName)))" "-DIBAction=void)__attribute__((ibaction)" -D__IPHONE_OS_VERSION_MIN_REQUIRED=40000 -iquote "/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/Event.build/Debug-iphonesimulator/HatFair.build/Hat Fair-generated-files.hmap" "-I/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/Event.build/Debug-iphonesimulator/HatFair.build/Hat Fair-own-target-headers.hmap" "-I/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/Event.build/Debug-iphonesimulator/HatFair.build/Hat Fair-all-target-headers.hmap" -iquote "/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/Event.build/Debug-iphonesimulator/HatFair.build/Hat Fair-project-headers.hmap" -I/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Products/Debug-iphonesimulator/include -I/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk/usr/include/libxml2 -I/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/Event.build/Debug-iphonesimulator/HatFair.build/DerivedSources/i386 -I/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/Event.build/Debug-iphonesimulator/HatFair.build/DerivedSources -F/Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Products/Debug-iphonesimulator -DNS_BLOCK_ASSERTIONS=1 --serialize-diagnostics /Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/PrecompiledHeaders/Event_Prefix-brpgiiwwokyynuheloumlvxlmurs/Event_Prefix.pch.dia -c /Users/waterskiingmithrill/Development/iPhone/Event/Event_Prefix.pch -o /Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/PrecompiledHeaders/Event_Prefix-brpgiiwwokyynuheloumlvxlmurs/Event_Prefix.pch.pth -MMD -MT dependencies -MF /Users/waterskiingmithrill/Library/Developer/Xcode/DerivedData/Event-cqyicuekijryjpbuuucigvdrxrdc/Build/Intermediates/PrecompiledHeaders/Event_Prefix-brpgiiwwokyynuheloumlvxlmurs/Event_Prefix.pch.d
  
  clang: error: no such file or directory: '/Users/waterskiingmithrill/Development/iPhone/Event/Event_Prefix.pch'
  clang: error: no input files
  Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 1
  </code></pre>
  
  <p>And I have no idea why <code>Event_Prefix.pch</code> is not there to be clanged. (I don't even know what clang is)  Any help, suggestions on how to debug, tips on how to fix, greatly appreciated.</p>