Debugging SenTestingKit to XCTest Linker Errors in Upgraded Xcode Projects
There’s a couple of (client) projects which I maintain which have been in existence for quite a while (one still has full iOS 5 support and hopefully we’ll be able to drop that soon), but they’re still well maintained and have reasonable test suites that have followed them through rather well. Sadly, Xcode can be a bit difficult and this time was no exception — although it did take a long time before the issue was seen.
In this project, I had a situation where the original SenTestingKit tests had been upgraded to use XCTest, but now they were failing to build. It looked to be a configuration error, so to come to the correct settings, I compared a new project (so, created straight out of Xcode with nothing else) and another project which was as new, but had Cocoapods attached. This allowed me to get the correct (well, current) configuration and apply it back to the old project.
In the end, it appeared to have been caused by Xcode’s automatic upgrader (which I’d run back when I upgraded the project) having mangled the build settings. Here’s how I fixed it:
Update the Framework Search Paths
The first set of errors related to the imported headers being missing, and looked like:
ld: framework not found -XCTest
In the test target under Xcode 5, the Header Search Paths listing should have looked like:
$(inherited)
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include
Switch the linker flag from SenTestingKit to XCTest
The next set of error messages related to the testing framework being missing and looked like:
Undefined symbols for architecture i386 "_OBJC_CLASS_$_XCTestCase"
This was caused by the old SenTestingKit still being linked aginst, and the
solution to this was to switch the “Other Linker Flags” setting to:
-Objc -framework XCTest
Of course, by the time someone else comes across the same issue (or a similar) one, the ideal configuration has likely changed somewhat. The trick to finding the solution is to build new Xcode projects from the templates and compare your configuration.