Why would Xcode not use the build configuration settings from my xcconfig file?

EDIT: I figured one could have this problem with any build configuration setting, not just OTHER_LDFLAGS and I've changed the title accordingly and removed irrelevant details from the question.

I have a simple Xcode project MyApp. MyApp.xcconfig is set as the configuration file for Debug builds. It has one line:

OTHER_LDFLAGS = -force_load /foo/bar

Though it knows MyApp.xcconfig sets OTHER_LDFLAGS Xcode doesn't want to use that setting. A blank space, instead of the value in MyApp.xcconfig, is highlighted in green in the build settings (see the bottom rows labelled "Other Linker Flags"):

Why is this the case? From what I've read, it seems like the resolved setting should be the one from the .xcconfig file. Is there a way to make it so?

I've also found that other settings in the xcconfig do resolve. But not OTHER_LDFLAGS.

The problem build setting (in this case OTHER_LDFLAGS) is being assigned an empty string, "", in MyApp's project.pbxproj file. Xcode sees that assignment and instead of ignoring it, overwrites your xcconfig setting. The solution is to delete the line in project.pbxproj.

• From the command line, open MyApp.xcodeproj/project.pbxproj in a text editor, e.g. Vim. In it you'll see Xcode keeps a bunch of information needed to build MyApp, including build configuration settings that you set in Xcode's UI.

• Scroll to the XCBuildConfiguration section. There you'll see your problem build setting (in this case OTHER_LDFLAGS) being assigned an empty string. Delete that line and save the file.

/* Begin XCBuildConfiguration section */
            .
            .
            .
            3729FD9E18B776ECB0A1990 /* Debug */ = {
                    isa = XCBuildConfiguration;
                    baseConfigurationReference = 4820F7A08BBB17C8164733A /* MyApp.xcconfig */;
                    buildSettings = {

                       /// delete this line ///
                         OTHER_LDFLAGS = "";

                    };
                    name = Debug;
            };
            .
            .
            .
/* End XCBuildConfiguration section */