# Objective
- Fixes#6711
## Solution
- Change the `path` function parameter of `dynamically_load_plugin` and `DynamicPluginExt::load_plugin` to a generic with `AsRef<OsStr>` bound
# Objective
Currently, `bevy_dynamic_plugin` simply panics on error. This makes it impossible to handle failures in applications that use this feature.
For example, I'd like to build an optional expansion for my game, that may not be distributed to all users. I want to use `bevy_dynamic_plugin` for loading it. I want my game to try to load it on startup, but continue without it if it cannot be loaded.
## Solution
- Make the `dynamically_load_plugin` function return a `Result`, so it can gracefully return loading errors.
- Create an error enum type, to provide useful information about the kind of error. This adds `thiserror` to the dependencies of `bevy_dynamic_plugin`, but that dependency is already used in other parts of bevy (such as `bevy_asset`), so not a big deal.
I chose not to change the behavior of the builder method in the App extension trait. I kept it as panicking. There is no clean way (that I'm aware of) to make a builder-style API that has fallible methods. So it is either a panic or a warning. I feel the panic is more appropriate.
---
## Changelog
### Changed
- `bevy_dynamic_plugin::dynamically_load_plugin` now returns `Result` instead of panicking, to allow for error handling
This is extracted out of eb8f973646476b4a4926ba644a77e2b3a5772159 and includes some additional changes to remove all references to AppBuilder and fix examples that still used App::build() instead of App::new(). In addition I didn't extract the sub app feature as it isn't ready yet.
You can use `git diff --diff-filter=M eb8f973646476b4a4926ba644a77e2b3a5772159` to find all differences in this PR. The `--diff-filtered=M` filters all files added in the original commit but not in this commit away.
Co-Authored-By: Carter Anderson <mcanders1@gmail.com>
