Not OP, but I'm on the same boat. We've been using a self-hosted GitLab CE instance for more than three years now, but we can't use the bare-bones approach of GitLab for issues tracking.
Trac allows us to fully customize the issues workflow, even for individual projects. We can have custom fields. We use several plugins (the extensibility of Trac is second to none!), even a few developed in-house, implementing custom validations and/or custom functionality.
Trac is very lightweight (as GitLab issues), but much, much more powerful and flexible. When you need the extra functionality, you can enable it, or install some 3rd party plugin that provides it, or develop your own plugin or component (which is really easy), without turning the whole thing in a bloated mess (like Jira).
The only thing I don't like about Trac is its glacial development speed, and its UI, which turns older and more outdated every year...
Sure. Please note I'm referring to Trac's UI, not GitLab's.
* it sucks on mobile. It's no responsive. At all;
* it's 2016 and I can't drag&drop a file to upload an attachment. Yes, there are a couple of 3rd party plugins that solve this, but this is one of those components that should have been added to the core ages ago;
* visualizing the work to do is harder than it should. A "visual" panel (like the one introduced by GitLab in its latest version) with drag&drop would be awesome.
* it's hard to customize. Things like changing colors, icons, padding, alignment, fonts are not at all straightforward unless you're willing to overwrite quite a lot of Trac's core CSS, and deal with the problems that might arise when you update. Trac rocks in extensibility and flexibility in almost every aspect, except for its UI and layout;
Looks nice indeed. I've used wiki pages with predefined ticket queries in different "panels", but they are static and non-interactive. I've also used a drag-and-drop "kanban cards" plugin, but without ticket queries/updates. I'd actually be a bit scared that ticket updates by drag and drop would lead to a lot of clutter in the ticket history. In the end I now mostly use the custom ticket query UI, although it sure could be improved.
