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Merged
epage merged 4 commits into from
Jul 22, 2026
+101 −26
Merged

fix(toml): warn on hyphenated lint names and duplicates #17051

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59edd7f
refactor(test): use underscores for lints in unrelated tests
raushan728 Jul 19, 2026
36830c4
test(toml): add baseline tests for hyphenated and duplicate lint names
raushan728 May 30, 2026
71c9cd0
fix(toml): warn on hyphen lint names
raushan728 Jul 19, 2026
8fd7c7b
fix(toml): warn on duplicate normalized lint names
raushan728 May 31, 2026
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16 changes: 16 additions & 0 deletions src/workspace/parser/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2698,7 +2698,23 @@ supported tools: {}",
if tool == "cargo" && !gctx.cli_unstable().cargo_lints {
warn_for_cargo_lint_feature(gctx, warnings);
}
let mut seen_normalized: HashMap<String, String> = HashMap::default();
for (name, config) in lints {
let normalized = name.replace('-', "_");
if name.contains('-') {
warnings.push(format!(
"`lints.{tool}.{name}` is deprecated in favor of \
`lints.{tool}.{normalized}` and will not work in a \
future edition"
));
}
if let Some(existing) = seen_normalized.get(&normalized) {
warnings.push(format!(
"duplicate lint `{existing}` in `[lints.{tool}]`, \
conflicts with `{name}` and will not work in a future edition"
));
}
seen_normalized.insert(normalized.clone(), name.to_string());
if let Some((prefix, suffix)) = name.split_once("::") {
if tool == prefix {
anyhow::bail!(
Expand Down
2 changes: 1 addition & 1 deletion tests/testsuite/install.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -3273,7 +3273,7 @@ authors = []
im-a-teapot = true

[lints.cargo]
im-a-teapot = "deny"
im_a_teapot = "deny"
"#,
)
.file("src/main.rs", "fn main() { let unused = 10; }")
Expand Down
17 changes: 8 additions & 9 deletions tests/testsuite/lints/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,7 @@ authors = []
im-a-teapot = true

[lints.cargo]
im-a-teapot = "warn"
im_a_teapot = "warn"
"#,
)
.file("src/lib.rs", "")
Expand All @@ -47,14 +47,13 @@ im-a-teapot = "warn"
foo.cargo("fetch -Zcargo-lints")
.masquerade_as_nightly_cargo(&["cargo-lints", "test-dummy-unstable"])
.with_stderr_data(str![[r#"
[WARNING] unknown lint: `im-a-teapot`
--> Cargo.toml:12:1
|
12 | im-a-teapot = "warn"
| ^^^^^^^^^^^
|
= [NOTE] `cargo::unknown_lints` is set to `warn` by default
= [HELP] there is a lint with a similar name: `im_a_teapot`
[WARNING] `im_a_teapot` is specified
--> Cargo.toml:9:1
|
9 | im-a-teapot = true
| ^^^^^^^^^^^^^^^^^^
|
= [NOTE] `cargo::im_a_teapot` is set to `warn` in `[lints]`
[WARNING] `foo` (manifest) generated 1 warning

"#]])
Expand Down
18 changes: 9 additions & 9 deletions tests/testsuite/lints/unknown_lints.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,7 @@ authors = []
[lints.cargo]
default = { level = "allow", priority = -1 }
unknown_lints = "warn"
this-lint-does-not-exist = "warn"
this_lint_does_not_exist = "warn"
"#,
)
.file("src/lib.rs", "")
Expand All @@ -26,10 +26,10 @@ this-lint-does-not-exist = "warn"
p.cargo("fetch -Zcargo-lints")
.masquerade_as_nightly_cargo(&["cargo-lints"])
.with_stderr_data(str![[r#"
[WARNING] unknown lint: `this-lint-does-not-exist`
[WARNING] unknown lint: `this_lint_does_not_exist`
--> Cargo.toml:11:1
|
11 | this-lint-does-not-exist = "warn"
11 | this_lint_does_not_exist = "warn"
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= [NOTE] `cargo::unknown_lints` is set to `warn` in `[lints]`
Expand All @@ -51,7 +51,7 @@ members = ["foo"]
[workspace.lints.cargo]
default = { level = "allow", priority = -1 }
unknown_lints = "warn"
this-lint-does-not-exist = "warn"
this_lint_does_not_exist = "warn"
"#,
)
.file(
Expand All @@ -73,10 +73,10 @@ workspace = true
p.cargo("fetch -Zcargo-lints")
.masquerade_as_nightly_cargo(&["cargo-lints"])
.with_stderr_data(str![[r#"
[WARNING] unknown lint: `this-lint-does-not-exist`
[WARNING] unknown lint: `this_lint_does_not_exist`
--> Cargo.toml:8:1
|
8 | this-lint-does-not-exist = "warn"
8 | this_lint_does_not_exist = "warn"
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= [NOTE] `cargo::unknown_lints` is set to `warn` in `[lints]`
Expand All @@ -98,7 +98,7 @@ members = ["foo"]
[workspace.lints.cargo]
default = { level = "allow", priority = -1 }
unknown_lints = "warn"
this-lint-does-not-exist = "warn"
this_lint_does_not_exist = "warn"
"#,
)
.file(
Expand All @@ -117,10 +117,10 @@ authors = []
p.cargo("fetch -Zcargo-lints")
.masquerade_as_nightly_cargo(&["cargo-lints"])
.with_stderr_data(str![[r#"
[WARNING] unknown lint: `this-lint-does-not-exist`
[WARNING] unknown lint: `this_lint_does_not_exist`
--> Cargo.toml:8:1
|
8 | this-lint-does-not-exist = "warn"
8 | this_lint_does_not_exist = "warn"
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= [NOTE] `cargo::unknown_lints` is set to `warn` in `[lints]`
Expand Down
74 changes: 67 additions & 7 deletions tests/testsuite/lints_table.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -125,7 +125,7 @@ fn invalid_type_in_lint_value() {
edition = "2015"

[workspace.lints.rust]
rust-2018-idioms = -1
rust_2018_idioms = -1
"#,
)
.file("src/lib.rs", "")
Expand All @@ -137,7 +137,7 @@ fn invalid_type_in_lint_value() {
[ERROR] invalid type: integer `-1`, expected a string or map
--> Cargo.toml:8:36
|
8 | rust-2018-idioms = -1
8 | rust_2018_idioms = -1
| ^^

"#]])
Expand All @@ -156,18 +156,18 @@ fn warn_on_unused_key() {
edition = "2015"

[workspace.lints.rust]
rust-2018-idioms = { level = "allow", unused = true }
rust_2018_idioms = { level = "allow", unused = true }
[lints.rust]
rust-2018-idioms = { level = "allow", unused = true }
rust_2018_idioms = { level = "allow", unused = true }
"#,
)
.file("src/lib.rs", "")
.build();

foo.cargo("check")
.with_stderr_data(str![[r#"
[WARNING] Cargo.toml: unused manifest key: `lints.rust.rust-2018-idioms.unused`
[WARNING] Cargo.toml: unused manifest key: `lints.rust.rust-2018-idioms.unused`
[WARNING] Cargo.toml: unused manifest key: `lints.rust.rust_2018_idioms.unused`
[WARNING] Cargo.toml: unused manifest key: `lints.rust.rust_2018_idioms.unused`
[WARNING] `foo` (manifest) generated 2 warnings
[CHECKING] foo v0.0.1 ([ROOT]/foo)
[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
Expand Down Expand Up @@ -697,7 +697,7 @@ fn doctest_respects_lints() {
authors = []

[lints.rust]
confusable-idents = 'allow'
confusable_idents = 'allow'
"#,
)
.file(
Expand Down Expand Up @@ -843,3 +843,63 @@ im_a_teapot = "warn"
"#]])
.run();
}

#[cargo_test]
fn hyphen_in_lint_name() {
let foo = project()
.file(
"Cargo.toml",
r#"
[package]
name = "foo"
version = "0.0.1"
edition = "2015"

[lints.rust]
unexpected-cfgs = "warn"
"#,
)
.file("src/lib.rs", "")
.build();

foo.cargo("check")
.with_stderr_data(str![[r#"
[WARNING] Cargo.toml: `lints.rust.unexpected-cfgs` is deprecated in favor of `lints.rust.unexpected_cfgs` and will not work in a future edition
[WARNING] `foo` (manifest) generated 1 warning
[CHECKING] foo v0.0.1 ([ROOT]/foo)
[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s

"#]])
.run();
}

#[cargo_test]
fn duplicate_lint_name_hyphen_and_underscore() {
let foo = project()
.file(
"Cargo.toml",
r#"
[package]
name = "foo"
version = "0.0.1"
edition = "2015"

[lints.rust]
unexpected_cfgs = "warn"
unexpected-cfgs = "allow"
"#,
)
.file("src/lib.rs", "")
.build();

foo.cargo("check")
.with_stderr_data(str![[r#"
[WARNING] Cargo.toml: `lints.rust.unexpected-cfgs` is deprecated in favor of `lints.rust.unexpected_cfgs` and will not work in a future edition
[WARNING] Cargo.toml: duplicate lint `unexpected-cfgs` in `[lints.rust]`, conflicts with `unexpected_cfgs` and will not work in a future edition
Comment on lines +897 to +898

@raushan728 raushan728 Jul 19, 2026 •
edited by rustbot
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The first one fires simply for using a hyphen in the lint name, and the second one fires because it creates a duplicate conflict after normalization.

View changes since the review

[WARNING] `foo` (manifest) generated 2 warnings
[CHECKING] foo v0.0.1 ([ROOT]/foo)
[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s

"#]])
.run();
}