For juniors it could be a positive signal though, if you're the kind of person that always looking to learn new things. Depends on the situation if you should show it or not: who are you trying to come across as?
If you have the resume, don't show it. Otherwise, do show it and let me know what parts you like and why some other parts are WIP (comments are great here).
Another thing to take in consideration is your own criticism. You might be really critical of the project since you're an exceptional programmer, and great programmers tend to move forward quickly and look back at their own old code with distaste. :)
- Programmers love good code
- Entrepreneurs love good products
So it's not always the quality of the codebase that matters when showing your side projects. Sometimes the product itself is more valuable.
Another recommendation I have is to pick side-projects that are small enough in scope to get finished. There's more satisfaction in that and also more useful for interview situations, arguably.