Problems linking static libraries in Xcode 4

All was right in the world until I upgraded to Xcode 4 a few days ago. Since then I've had endless problems getting things to work as they should. And I have a crucial update I need to release. I've tried every permutation of settings I can think of, restarted, reinstalled Xcode, reverted to old versions of my files, everything.

My project links to three static libraries, contained in three other projects. I have used the standard processes to link libraries (drag the project files into mine, add their products as target dependencies, add the lib---.a files to the Link Binary With Libraries phase). And actually, I have no problem compiling with the Debug Build Configuration, either for the simulator or my test device.

Where everything goes sideways is when I compile with the Release Build Configuration, or when I try to Archive. I've gotten many different errors depending on my settings, but most are variations on this:

ld: warning: ignoring file [...]/Build/Products/Debug-iphonesimulator/libGDataTouchStaticLib.a, file was built for archive which is not the architecture being linked (armv6) Undefined symbols for architecture armv6:

开发者_运维知识库 "_OBJC_CLASS_$_GDataSpreadsheetData", referenced from: objc-class-ref in ExportViewController.o

I can't understand why it's even looking at Products in the Debug-iphonesimulator directory (I swear, everything I'm linking to reveals itself in the Finder to be in the proper Release-iphoneos directory).

I have put a ridiculous number of hours into fixing this, really need help! Thank you!

Please check this question and answer. I encountered same problem and fixed it.

Xcode4 Linking Problem. File was built for archive which is not the architecture being linked (arm6)

I solved this problem by copying the .a lib files from the Release-iphoneos directory to the Debug-iphonesimulator directory so that the correct files would be found even though Xcode was looking in the wrong directory.

However, then I encountered the problem raised here of a multi-application bundle -- and the solution given didn't work for me. Finally gave up and reinstalled Xcode 3. Compiled, archived, and uploaded to the App Store in 20 minutes. Will be some time, and several dot-releases, before I give Xcode 4 another shot.

You may have -DGDATA_REQUIRE_SERVICE_INCLUDES=1 enabled in your other C flags for the GDataTouchStaticLib target. If so, add the service you need, in this case, spreadsheets, by adding -DGDATA_INCLUDE_SPREADSHEET_SERVICE=1 to your Other C Flags. Or if you don't want GData to require service includes (which will build everything into the static lib, not just what you need), just remove the DGDATA_REQUIRE_SERVICE_INCLUDES flag.