When multiple traits are applicable for method, do not specialize main message to the first one that applied#153679
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estebank wants to merge 1 commit intorust-lang:mainfrom
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When multiple traits are applicable for method, do not specialize main message to the first one that applied#153679estebank wants to merge 1 commit intorust-lang:mainfrom
estebank wants to merge 1 commit intorust-lang:mainfrom
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…n message to the first one that applied
When calling a method that appears on `Iterator`, we often say "`Foo` is not an iterator", even if that method exists in other traits, which is quite confusing and many times nonsensical. Now, if we mention multiple traits we revert the main message back:
```
error[E0599]: no method named `take` found for struct `Foo` in the current scope
--> $DIR/method-call-err-msg.rs:19:7
|
LL | pub struct Foo;
| -------------- method `take` not found for this struct because it doesn't satisfy `Foo: Iterator`
...
LL | / y.zero()
LL | | .take()
| | -^^^^ `Foo` is not an iterator
| |______|
|
|
= note: the following trait bounds were not satisfied:
`Foo: Iterator`
which is required by `&mut Foo: Iterator`
note: the trait `Iterator` must be implemented
--> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
= help: items from traits can only be used if the trait is implemented and in scope
= note: the following traits define an item `take`, perhaps you need to implement one of them:
candidate rust-lang#1: `Iterator`
candidate rust-lang#2: `std::io::Read`
```
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rustbot has assigned @JonathanBrouwer. Use Why was this reviewer chosen?The reviewer was selected based on:
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JohnTitor
reviewed
Mar 11, 2026
| name = item_name, | ||
| ) | ||
| }; | ||
| if candidates_len > 1 { |
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I think this is a bit loose and could cause a regression when it's still unsatisfied but multiple traits are found while a method actually existing. Maybe we can add a check for such a case not to override.
| --> $DIR/method-call-err-msg.rs:19:7 | ||
| | | ||
| LL | pub struct Foo; | ||
| | -------------- method `take` not found for this struct because it doesn't satisfy `Foo: Iterator` |
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The error message is now correct, but the labels here still assume that Iterator is the correct trait
JonathanBrouwer
requested changes
Mar 11, 2026
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Reminder, once the PR becomes ready for a review, use |
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When calling a method that appears on
Iterator, we often say "Foois not an iterator", even if that method exists in other traits, which is quite confusing and many times nonsensical. Now, if we mention multiple traits we revert the main message back:Fix #113550.