I did the symlinking. As I understand it, linking doesn't matter as long as the absolute path resolves to the correct .so and the version numbering is also correct. I have used this type of linking before and never had any problems with it.
For thoroughness, I redid the linking in the way you describe and relinked the binary but it didn't help.
I took the binary elements of these libraries from what is now a deprecated package from Jessie. I had previously used on Sid, Jessie and then Stretch.
Refs:
https://packages.debian.org/search?keywords=libdispatch
https://github.com/mheily/libkqueue
https://github.com/apple/swift-corelibs-libdispatch