In order to gain access to all the files from the repository, you should clone it.
git clone --recursive https://github.com/SDWebImage/SDWebImage.git
... TO BE CHECKED AND DESCRIBED IN DETAIL
Open the "Build Settings" tab, in the "Linking" section, locate the "Other Linker Flags" setting and add the "-ObjC" flag:
Alternatively, if this causes compilation problems with frameworks that extend optional libraries, such as Parse, RestKit or opencv2, instead of the -ObjC flag use:
-force_load SDWebImage.framework/Versions/Current/SDWebImage
If you're using Cocoa Pods and have any frameworks that extend optional libraries, such as Parsen RestKit or opencv2, instead of the -ObjC flag use:
-force_load $(TARGET_BUILD_DIR)/libPods.a
and this:
$(inherited)