Is this *too much*? Historically, having two crate versions in your dependency tree and accidentally mixing types from them led to horribly obtuse error messages (expected `Foo`, found `Foo`). We've slowly chipped away at them, but somethings I fear I might have gone overboard with detail. 😬
![Rust compiler error output:
error[E0277]: the trait bound `CustomErrorHandler: ErrorHandler` is not satisfied
--> src/main.rs:5:17
|
5 | cnb_runtime(CustomErrorHandler {});
| ----------- ^^^^^^^^^^^^^^^^^^^^^ the trait `ErrorHandler` is not implemented for `CustomErrorHandler`
| |
| required by a bound introduced by this call
|
help: there are multiple different versions of crate `c` in the dependency graph
--> src/main.rs:1:5
|
1 | use b::CustomErrorHandler;
| ^ one version of crate `c` is used here, as a dependency of crate `b`
2 | use c::cnb_runtime;
| ^ one version of crate `c` is used here, as a direct dependency of the current crate
note: two types coming from two different versions of the same crate are different types even if they look the same
--> ~/c-v0.2/src/lib.rs:1:1
|
1 | pub trait ErrorHandler {}
| ^^^^^^^^^^^^^^^^^^^^^^ this is the required trait
|
::: ~/b/src/lib.rs:1:1
|
1 | pub struct CustomErrorHandler {}
| ----------------------------- this type doesn't implement the required trait
|
::: ~/c-v0.1/src/lib.rs:1:1
|
1 | pub trait ErrorHandler {}
| ---------------------- this is the found trait
= help: you can use `cargo tree` to explore your dependency tree
note: required by a bound in `cnb_runtime`
--> ~/c-v0.2/src/lib.rs:3:41
|
3 | pub fn cnb_runtime(_error_handler: impl ErrorHandler) {}
| ^^^^^^^^^^^^ required by this bound in `cnb_runtime`](https://fedi.ml/photo/preview/640/582508 "Rust compiler error output:
error[E0277]: the trait bound `CustomErrorHandler: ErrorHandler` is not satisfied
--> src/main.rs:5:17
|
5 | cnb_runtime(CustomErrorHandler {});
| ----------- ^^^^^^^^^^^^^^^^^^^^^ the trait `ErrorHandler` is not implemented for `CustomErrorHandler`
| |
| required by a bound introduced by this call
|
help: there are multiple different versions of crate `c` in the dependency graph
--> src/main.rs:1:5
|
1 | use b::CustomErrorHandler;
| ^ one version of crate `c` is used here, as a dependency of crate `b`
2 | use c::cnb_runtime;
| ^ one version of crate `c` is used here, as a direct dependency of the current crate
note: two types coming from two different versions of the same crate are different types even if they look the same
--> ~/c-v0.2/src/lib.rs:1:1
|
1 | pub trait ErrorHandler {}
| ^^^^^^^^^^^^^^^^^^^^^^ this is the required trait
|
::: ~/b/src/lib.rs:1:1
|
1 | pub struct CustomErrorHandler {}
| ----------------------------- this type doesn't implement the required trait
|
::: ~/c-v0.1/src/lib.rs:1:1
|
1 | pub trait ErrorHandler {}
| ---------------------- this is the found trait
= help: you can use `cargo tree` to explore your dependency tree
note: required by a bound in `cnb_runtime`
--> ~/c-v0.2/src/lib.rs:3:41
|
3 | pub fn cnb_runtime(_error_handler: impl ErrorHandler) {}
| ^^^^^^^^^^^^ required by this bound in `cnb_runtime`")
Matt Campbell
in reply to Esteban Küber • • •Esteban Küber
in reply to Matt Campbell • • •