# Objective
- `bevy_ui` does not build without the `bevy_text` feature due to
improper feature gating.
- Specifically, `MeasureArgs<'a>` had an unused lifetime `'a` without
`bevy_text` enabled. This is because it stores a reference to a
`cosmic_text::FontSystem`.
- This was caught by `flag-frenzy` in [this
run](https://github.com/TheBevyFlock/flag-frenzy/actions/runs/10024258523/job/27706132250).
## Solution
- Add a `PhantomData` to `MeasureArgs<'a>` in order to maintain its
lifetime argument.
- I also named it `font_system`, after the feature-gated argument that
actually needs a lifetime, for usability. Please comment if you have a
better solution!
- Move some unused imports to be behind the `bevy_text` feature gate.
## Testing
```bash
# Fails on main.
cargo check -p bevy_ui --no-default-features
# Succeeds on main.
cargo check -p bevy_ui --no-default-features -F bevy_text
```
---
## Migration Guide
**This is not a breaking change for users migrating from 0.14, since
`MeasureArgs` did not exist then.**
When the `bevy_text` feature is disabled for `bevy_ui`, the type of the
`MeasureArgs::font_system` field is now a `PhantomData` instead of being
removed entirely. This is in order to keep the lifetime parameter, even
though it is unused without text being enabled.
cd497152bb