By default dub does not build C files (as evidenced by your command line). It may not even let you I don't know, but try:```json "sourceFiles" : ["source/zstdc_binding.c"] ```
Ok, this works. So Dub is not picking any C files by default. Thanks for the hint.
I will spent some time to prepare a fix for Dub, so that C files (only '.c' files, no headers) in detected/configured source directories are picked up as well.
