Question

I’m trying to upgrade my iOS project to using ARC.
When starting the conversion via Edit -> Refactor -> Convert to Objective-C ARC, I select my target, deselect linked libraries and press check.
Next I get the following error:

clang: error: argument unused during compilation: '-ccc-arcmt-check'
Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 1

Some idea how to resolve this? Xcode does not even try to start converting the source files.

Note that I’ve got several targets in my project file sharing some source files. The conversion dialog only displays the target set in the current scheme.

I’ve already successfully converted another (static library) project, so the Xcode setup should be ok.

EDIT: I’ve activated Continue building after errors in Xcode’s preferences, at least now I see all ARC errors. Let’s see if this lets me convert to ARC.

EDIT2: I get this error for every source file of my target, I do not want to use ARC for – so it seems as if the compiler has a problem with concurrent flags -ccc-arcmt-check and -fno-objc-arc.

Answer 1

I found it out: Turn off Treat Warnings as Errors in Project Settings.