Additionnal informations:
It seems that the #9 library corresponds to the library entry (from otool -L UnrealPak) :
@rpath/libicuuc.53.1.dylib (compatibility version 53.0.0, current version 53.1.0)
However this library is present here:
/Users/our_user/Desktop/Developers/UDK/our_checkout/Engine/Binaries/ThirdParty/ICU/icu4c-53_1/Mac/libicuuc.53.1.dylib
But it seems UnrealPak can’t find it ?