I’m running into the same issue. It seems the shell commandline to build doesn’t do so with the correct dylib. Notice in the below example, the output is UE4Editor-MyProject-6889.dylib but the shell script tryies to build 8064.
Everytime I compile, I get a new number, however the 8064 persists.
Info Setting up Mono
Info /Users/Shared/UnrealEngine/4.9/Engine /Users/Shared/UnrealEngine/4.9/Engine/Binaries/Mac
Info Compiling game modules for hot reload
Info Performing 2 actions (4 in parallel)
Info [1/2] Link UE4Editor-MyProject-6889.dylib
Info [2/2] sh -c 'rm -rf "/Users/Twigg/Documents/Unreal Projects/MyProject/Binaries/Mac/UE4Editor-MyProject-8064.dSYM"; "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/"dsymutil -f "/Users/Twigg/Documents/Unreal Projects/MyProject/Binaries/Mac/UE4Editor-MyProject-8064.dylib" -o "/Users/Twigg/Documents/Unreal Projects/MyProject/Binaries/Mac/UE4Editor-MyProject-8064.dSYM"'
Info error: unable to open executable '/Users/Twigg/Documents/Unreal Projects/MyProject/Binaries/Mac/UE4Editor-MyProject-8064.dylib': No such file or directory