diff --git a/src/cargo/util/toml/mod.rs b/src/cargo/util/toml/mod.rs
index 093f82638a1..16cba3cd3a2 100644
--- a/src/cargo/util/toml/mod.rs
+++ b/src/cargo/util/toml/mod.rs
@@ -904,9 +904,14 @@ fn inner_dependency_inherit_with<'a>(
                 this could become a hard error in the future"
         ))
     }
-    if dependency.default_features.is_some() && dependency.default_features2.is_some() {
-        warn_on_deprecated("default-features", name, "dependency", warnings);
-    }
+    deprecated_underscore(
+        &dependency.default_features2,
+        &dependency.default_features,
+        "default-features",
+        name,
+        "dependency",
+        warnings,
+    );
     inherit()?.get_dependency(name, package_root).map(|d| {
         match d {
             manifest::TomlDependency::Simple(s) => {
@@ -1157,18 +1162,28 @@ fn to_real_manifest(
     }
 
     validate_dependencies(original_toml.dependencies.as_ref(), None, None, warnings)?;
-    if original_toml.dev_dependencies.is_some() && original_toml.dev_dependencies2.is_some() {
-        warn_on_deprecated("dev-dependencies", package_name, "package", warnings);
-    }
+    deprecated_underscore(
+        &original_toml.dev_dependencies2,
+        &original_toml.dev_dependencies,
+        "dev-dependencies",
+        package_name,
+        "package",
+        warnings,
+    );
     validate_dependencies(
         original_toml.dev_dependencies(),
         None,
         Some(DepKind::Development),
         warnings,
     )?;
-    if original_toml.build_dependencies.is_some() && original_toml.build_dependencies2.is_some() {
-        warn_on_deprecated("build-dependencies", package_name, "package", warnings);
-    }
+    deprecated_underscore(
+        &original_toml.build_dependencies2,
+        &original_toml.build_dependencies,
+        "build-dependencies",
+        package_name,
+        "package",
+        warnings,
+    );
     validate_dependencies(
         original_toml.build_dependencies(),
         None,
@@ -1185,18 +1200,28 @@ fn to_real_manifest(
             None,
             warnings,
         )?;
-        if platform.build_dependencies.is_some() && platform.build_dependencies2.is_some() {
-            warn_on_deprecated("build-dependencies", name, "platform target", warnings);
-        }
+        deprecated_underscore(
+            &platform.build_dependencies2,
+            &platform.build_dependencies,
+            "build-dependencies",
+            name,
+            "platform target",
+            warnings,
+        );
         validate_dependencies(
             platform.build_dependencies(),
             platform_kind.as_ref(),
             Some(DepKind::Build),
             warnings,
         )?;
-        if platform.dev_dependencies.is_some() && platform.dev_dependencies2.is_some() {
-            warn_on_deprecated("dev-dependencies", name, "platform target", warnings);
-        }
+        deprecated_underscore(
+            &platform.dev_dependencies2,
+            &platform.dev_dependencies,
+            "dev-dependencies",
+            name,
+            "platform target",
+            warnings,
+        );
         validate_dependencies(
             platform.dev_dependencies(),
             platform_kind.as_ref(),
@@ -1885,14 +1910,14 @@ fn detailed_dep_to_dependency<P: ResolveToPath + Clone>(
 
     let version = orig.version.as_deref();
     let mut dep = Dependency::parse(pkg_name, version, new_source_id)?;
-    if orig.default_features.is_some() && orig.default_features2.is_some() {
-        warn_on_deprecated(
-            "default-features",
-            name_in_toml,
-            "dependency",
-            manifest_ctx.warnings,
-        );
-    }
+    deprecated_underscore(
+        &orig.default_features2,
+        &orig.default_features,
+        "default-features",
+        name_in_toml,
+        "dependency",
+        manifest_ctx.warnings,
+    );
     dep.set_features(orig.features.iter().flatten())
         .set_default_features(orig.default_features().unwrap_or(true))
         .set_optional(orig.optional.unwrap_or(false))
@@ -2304,12 +2329,25 @@ fn emit_diagnostic(
 }
 
 /// Warn about paths that have been deprecated and may conflict.
-fn warn_on_deprecated(new_path: &str, name: &str, kind: &str, warnings: &mut Vec<String>) {
-    let old_path = new_path.replace("-", "_");
-    warnings.push(format!(
-        "conflicting between `{new_path}` and `{old_path}` in the `{name}` {kind}.\n
-        `{old_path}` is ignored and not recommended for use in the future"
-    ))
+fn deprecated_underscore<T>(
+    old: &Option<T>,
+    new: &Option<T>,
+    new_path: &str,
+    name: &str,
+    kind: &str,
+    warnings: &mut Vec<String>,
+) {
+    if old.is_some() && new.is_some() {
+        let old_path = new_path.replace("-", "_");
+        warnings.push(format!(
+            "unused manifest key `{old_path}` in the `{name}` {kind}"
+        ))
+    } else if old.is_some() {
+        let old_path = new_path.replace("-", "_");
+        warnings.push(format!(
+            "`{old_path}` is deprecated in favor of `{new_path}` and will not work in the 2024 edition\n(in the `{name}` {kind})"
+        ))
+    }
 }
 
 fn warn_on_unused(unused: &BTreeSet<String>, warnings: &mut Vec<String>) {
diff --git a/src/cargo/util/toml/targets.rs b/src/cargo/util/toml/targets.rs
index 937177c9583..9c1268a39b8 100644
--- a/src/cargo/util/toml/targets.rs
+++ b/src/cargo/util/toml/targets.rs
@@ -25,7 +25,7 @@ use crate::core::compiler::CrateType;
 use crate::core::{Edition, Feature, Features, Target};
 use crate::util::errors::CargoResult;
 use crate::util::restricted_names;
-use crate::util::toml::warn_on_deprecated;
+use crate::util::toml::deprecated_underscore;
 
 const DEFAULT_TEST_DIR_NAME: &'static str = "tests";
 const DEFAULT_BENCH_DIR_NAME: &'static str = "benches";
@@ -1102,23 +1102,23 @@ fn name_or_panic(target: &TomlTarget) -> &str {
 }
 
 fn validate_proc_macro(target: &TomlTarget, kind: &str, warnings: &mut Vec<String>) {
-    if target.proc_macro.is_some() && target.proc_macro2.is_some() {
-        warn_on_deprecated(
-            "proc-macro",
-            name_or_panic(target),
-            format!("{kind} target").as_str(),
-            warnings,
-        );
-    }
+    deprecated_underscore(
+        &target.proc_macro2,
+        &target.proc_macro,
+        "proc-macro",
+        name_or_panic(target),
+        format!("{kind} target").as_str(),
+        warnings,
+    );
 }
 
 fn validate_crate_types(target: &TomlTarget, kind: &str, warnings: &mut Vec<String>) {
-    if target.crate_type.is_some() && target.crate_type2.is_some() {
-        warn_on_deprecated(
-            "crate-type",
-            name_or_panic(target),
-            format!("{kind} target").as_str(),
-            warnings,
-        );
-    }
+    deprecated_underscore(
+        &target.crate_type2,
+        &target.crate_type,
+        "crate-type",
+        name_or_panic(target),
+        format!("{kind} target").as_str(),
+        warnings,
+    );
 }
diff --git a/tests/testsuite/bad_config.rs b/tests/testsuite/bad_config.rs
index cbd216491e7..e8fb1ad4065 100644
--- a/tests/testsuite/bad_config.rs
+++ b/tests/testsuite/bad_config.rs
@@ -804,6 +804,611 @@ Caused by:
         .run();
 }
 
+#[cargo_test]
+fn dev_dependencies2() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2018"
+
+                [dev_dependencies]
+                a = {path = "a"}
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.0.1"
+                edition = "2015"
+            "#,
+        )
+        .file("a/src/lib.rs", "")
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] `dev_dependencies` is deprecated in favor of `dev-dependencies` and will not work in the 2024 edition
+(in the `foo` package)
+"
+        )
+        .run();
+}
+
+#[cargo_test]
+fn dev_dependencies2_conflict() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2018"
+
+                [dev-dependencies]
+                a = {path = "a"}
+                [dev_dependencies]
+                a = {path = "a"}
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.0.1"
+                edition = "2015"
+            "#,
+        )
+        .file("a/src/lib.rs", "")
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] unused manifest key `dev_dependencies` in the `foo` package
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn build_dependencies2() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2018"
+
+                [build_dependencies]
+                a = {path = "a"}
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.0.1"
+                edition = "2015"
+            "#,
+        )
+        .file("a/src/lib.rs", "")
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] `build_dependencies` is deprecated in favor of `build-dependencies` and will not work in the 2024 edition
+(in the `foo` package)
+"
+        )
+        .run();
+}
+
+#[cargo_test]
+fn build_dependencies2_conflict() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2018"
+
+                [build-dependencies]
+                a = {path = "a"}
+                [build_dependencies]
+                a = {path = "a"}
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.0.1"
+                edition = "2015"
+            "#,
+        )
+        .file("a/src/lib.rs", "")
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] unused manifest key `build_dependencies` in the `foo` package
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn lib_crate_type2() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.5.0"
+                edition = "2015"
+                authors = ["wycats@example.com"]
+
+                [lib]
+                name = "foo"
+                crate_type = ["staticlib", "dylib"]
+            "#,
+        )
+        .file("src/lib.rs", "pub fn foo() {}")
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] `crate_type` is deprecated in favor of `crate-type` and will not work in the 2024 edition
+(in the `foo` library target)
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn lib_crate_type2_conflict() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.5.0"
+                edition = "2015"
+                authors = ["wycats@example.com"]
+
+                [lib]
+                name = "foo"
+                crate-type = ["rlib", "dylib"]
+                crate_type = ["staticlib", "dylib"]
+            "#,
+        )
+        .file("src/lib.rs", "pub fn foo() {}")
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] unused manifest key `crate_type` in the `foo` library target
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn examples_crate_type2() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.5.0"
+                edition = "2015"
+                authors = ["wycats@example.com"]
+
+                [[example]]
+                name = "ex"
+                path = "examples/ex.rs"
+                crate_type = ["proc_macro"]
+                [[example]]
+                name = "goodbye"
+                path = "examples/ex-goodbye.rs"
+                crate_type = ["rlib", "staticlib"]
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "examples/ex.rs",
+            r#"
+                fn main() { println!("ex"); }
+            "#,
+        )
+        .file(
+            "examples/ex-goodbye.rs",
+            r#"
+                fn main() { println!("goodbye"); }
+            "#,
+        )
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] `crate_type` is deprecated in favor of `crate-type` and will not work in the 2024 edition
+(in the `ex` example target)
+[WARNING] `crate_type` is deprecated in favor of `crate-type` and will not work in the 2024 edition
+(in the `goodbye` example target)
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn examples_crate_type2_conflict() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.5.0"
+                edition = "2015"
+                authors = ["wycats@example.com"]
+
+                [[example]]
+                name = "ex"
+                path = "examples/ex.rs"
+                crate-type = ["rlib", "dylib"]
+                crate_type = ["proc_macro"]
+                [[example]]
+                name = "goodbye"
+                path = "examples/ex-goodbye.rs"
+                crate-type = ["rlib", "dylib"]
+                crate_type = ["rlib", "staticlib"]
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "examples/ex.rs",
+            r#"
+                fn main() { println!("ex"); }
+            "#,
+        )
+        .file(
+            "examples/ex-goodbye.rs",
+            r#"
+                fn main() { println!("goodbye"); }
+            "#,
+        )
+        .build();
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] unused manifest key `crate_type` in the `ex` example target
+[WARNING] unused manifest key `crate_type` in the `goodbye` example target
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn cargo_platform_build_dependencies2() {
+    let host = rustc_host();
+    let p = project()
+        .file(
+            "Cargo.toml",
+            &format!(
+                r#"
+                    [package]
+                    name = "foo"
+                    version = "0.5.0"
+                    edition = "2015"
+                    authors = ["wycats@example.com"]
+                    build = "build.rs"
+
+                    [target.{host}.build_dependencies]
+                    build = {{ path = "build" }}
+                "#,
+                host = host
+            ),
+        )
+        .file("src/main.rs", "fn main() { }")
+        .file(
+            "build.rs",
+            "extern crate build; fn main() { build::build(); }",
+        )
+        .file("build/Cargo.toml", &basic_manifest("build", "0.5.0"))
+        .file("build/src/lib.rs", "pub fn build() {}")
+        .build();
+
+    p.cargo("check")
+        .with_stderr_contains(
+            format!("\
+[WARNING] `build_dependencies` is deprecated in favor of `build-dependencies` and will not work in the 2024 edition
+(in the `{host}` platform target)
+")
+        )
+        .run();
+}
+
+#[cargo_test]
+fn cargo_platform_build_dependencies2_conflict() {
+    let host = rustc_host();
+    let p = project()
+        .file(
+            "Cargo.toml",
+            &format!(
+                r#"
+                    [package]
+                    name = "foo"
+                    version = "0.5.0"
+                    edition = "2015"
+                    authors = ["wycats@example.com"]
+                    build = "build.rs"
+
+                    [target.{host}.build-dependencies]
+                    build = {{ path = "build" }}
+                    [target.{host}.build_dependencies]
+                    build = {{ path = "build" }}
+                "#,
+                host = host
+            ),
+        )
+        .file("src/main.rs", "fn main() { }")
+        .file(
+            "build.rs",
+            "extern crate build; fn main() { build::build(); }",
+        )
+        .file("build/Cargo.toml", &basic_manifest("build", "0.5.0"))
+        .file("build/src/lib.rs", "pub fn build() {}")
+        .build();
+
+    p.cargo("check")
+        .with_stderr_contains(format!(
+            "\
+[WARNING] unused manifest key `build_dependencies` in the `{host}` platform target
+"
+        ))
+        .run();
+}
+
+#[cargo_test]
+fn cargo_platform_dev_dependencies2() {
+    let host = rustc_host();
+    let p = project()
+        .file(
+            "Cargo.toml",
+            &format!(
+                r#"
+                    [package]
+                    name = "foo"
+                    version = "0.5.0"
+                    edition = "2015"
+                    authors = ["wycats@example.com"]
+
+                    [target.{host}.dev_dependencies]
+                    dev = {{ path = "dev" }}
+                "#,
+                host = host
+            ),
+        )
+        .file("src/main.rs", "fn main() { }")
+        .file(
+            "tests/foo.rs",
+            "extern crate dev; #[test] fn foo() { dev::dev() }",
+        )
+        .file("dev/Cargo.toml", &basic_manifest("dev", "0.5.0"))
+        .file("dev/src/lib.rs", "pub fn dev() {}")
+        .build();
+
+    p.cargo("check")
+        .with_stderr_contains(
+            format!("\
+[WARNING] `dev_dependencies` is deprecated in favor of `dev-dependencies` and will not work in the 2024 edition
+(in the `{host}` platform target)
+")
+        )
+        .run();
+}
+
+#[cargo_test]
+fn cargo_platform_dev_dependencies2_conflict() {
+    let host = rustc_host();
+    let p = project()
+        .file(
+            "Cargo.toml",
+            &format!(
+                r#"
+                    [package]
+                    name = "foo"
+                    version = "0.5.0"
+                    edition = "2015"
+                    authors = ["wycats@example.com"]
+
+                    [target.{host}.dev-dependencies]
+                    dev = {{ path = "dev" }}
+                    [target.{host}.dev_dependencies]
+                    dev = {{ path = "dev" }}
+                "#,
+                host = host
+            ),
+        )
+        .file("src/main.rs", "fn main() { }")
+        .file(
+            "tests/foo.rs",
+            "extern crate dev; #[test] fn foo() { dev::dev() }",
+        )
+        .file("dev/Cargo.toml", &basic_manifest("dev", "0.5.0"))
+        .file("dev/src/lib.rs", "pub fn dev() {}")
+        .build();
+
+    p.cargo("check")
+        .with_stderr_contains(format!(
+            "\
+[WARNING] unused manifest key `dev_dependencies` in the `{host}` platform target
+"
+        ))
+        .run();
+}
+
+#[cargo_test]
+fn default_features2() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2015"
+                authors = []
+
+                [dependencies]
+                a = { path = "a", features = ["f1"], default_features = false }
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.1.0"
+                edition = "2015"
+                authors = []
+
+                [features]
+                default = ["f1"]
+                f1 = []
+            "#,
+        )
+        .file("a/src/lib.rs", "")
+        .build();
+
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] `default_features` is deprecated in favor of `default-features` and will not work in the 2024 edition
+(in the `a` dependency)
+"
+        )
+        .run();
+}
+
+#[cargo_test]
+fn default_features2_conflict() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2015"
+                authors = []
+
+                [dependencies]
+                a = { path = "a", features = ["f1"], default-features = false, default_features = false }
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "a/Cargo.toml",
+            r#"
+                [package]
+                name = "a"
+                version = "0.1.0"
+                edition = "2015"
+                authors = []
+
+                [features]
+                default = ["f1"]
+                f1 = []
+            "#,
+        )
+        .file("a/src/lib.rs", "")
+        .build();
+
+    p.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] unused manifest key `default_features` in the `a` dependency
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn proc_macro2() {
+    let foo = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2015"
+                [lib]
+                proc_macro = true
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+
+    foo.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] `proc_macro` is deprecated in favor of `proc-macro` and will not work in the 2024 edition
+(in the `foo` library target)
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn proc_macro2_conflict() {
+    let foo = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2015"
+                [lib]
+                proc-macro = false
+                proc_macro = true
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+
+    foo.cargo("check")
+        .with_stderr_contains(
+            "\
+[WARNING] unused manifest key `proc_macro` in the `foo` library target
+",
+        )
+        .run();
+}
+
 #[cargo_test]
 fn invalid_toml_historically_allowed_fails() {
     let p = project()
diff --git a/tests/testsuite/bench.rs b/tests/testsuite/bench.rs
index ea646b398d8..eb9c92c1edd 100644
--- a/tests/testsuite/bench.rs
+++ b/tests/testsuite/bench.rs
@@ -853,7 +853,7 @@ fn bench_dylib() {
 
                 [lib]
                 name = "foo"
-                crate_type = ["dylib"]
+                crate-type = ["dylib"]
 
                 [dependencies.bar]
                 path = "bar"
@@ -895,7 +895,7 @@ fn bench_dylib() {
 
                 [lib]
                 name = "bar"
-                crate_type = ["dylib"]
+                crate-type = ["dylib"]
             "#,
         )
         .file("bar/src/lib.rs", "pub fn baz() {}")
diff --git a/tests/testsuite/build.rs b/tests/testsuite/build.rs
index daa605fdfd4..7da48de80cf 100644
--- a/tests/testsuite/build.rs
+++ b/tests/testsuite/build.rs
@@ -1496,7 +1496,7 @@ fn cargo_default_env_metadata_env_var() {
 
                 [lib]
                 name = "bar"
-                crate_type = ["dylib"]
+                crate-type = ["dylib"]
             "#,
         )
         .file("bar/src/lib.rs", "// hello")
@@ -2089,7 +2089,7 @@ fn many_crate_types_old_style_lib_location() {
                 [lib]
 
                 name = "foo"
-                crate_type = ["rlib", "dylib"]
+                crate-type = ["rlib", "dylib"]
             "#,
         )
         .file("src/foo.rs", "pub fn foo() {}")
@@ -2123,7 +2123,7 @@ fn many_crate_types_correct() {
                 [lib]
 
                 name = "foo"
-                crate_type = ["rlib", "dylib"]
+                crate-type = ["rlib", "dylib"]
             "#,
         )
         .file("src/lib.rs", "pub fn foo() {}")
@@ -2151,7 +2151,7 @@ fn set_both_dylib_and_cdylib_crate_types() {
                 [lib]
 
                 name = "foo"
-                crate_type = ["cdylib", "dylib"]
+                crate-type = ["cdylib", "dylib"]
             "#,
         )
         .file("src/lib.rs", "pub fn foo() {}")
@@ -2169,157 +2169,6 @@ Caused by:
         .run();
 }
 
-#[cargo_test]
-fn dev_dependencies_conflicting_warning() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.1.0"
-                edition = "2018"
-
-                [dev-dependencies]
-                a = {path = "a"}
-                [dev_dependencies]
-                a = {path = "a"}
-            "#,
-        )
-        .file("src/lib.rs", "")
-        .file(
-            "a/Cargo.toml",
-            r#"
-                [package]
-                name = "a"
-                version = "0.0.1"
-                edition = "2015"
-            "#,
-        )
-        .file("a/src/lib.rs", "")
-        .build();
-    p.cargo("build")
-        .with_stderr_contains(
-"[WARNING] conflicting between `dev-dependencies` and `dev_dependencies` in the `foo` package.\n
-        `dev_dependencies` is ignored and not recommended for use in the future"
-        )
-        .run();
-}
-
-#[cargo_test]
-fn build_dependencies_conflicting_warning() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.1.0"
-                edition = "2018"
-
-                [build-dependencies]
-                a = {path = "a"}
-                [build_dependencies]
-                a = {path = "a"}
-            "#,
-        )
-        .file("src/lib.rs", "")
-        .file(
-            "a/Cargo.toml",
-            r#"
-                [package]
-                name = "a"
-                version = "0.0.1"
-                edition = "2015"
-            "#,
-        )
-        .file("a/src/lib.rs", "")
-        .build();
-    p.cargo("build")
-        .with_stderr_contains(
-"[WARNING] conflicting between `build-dependencies` and `build_dependencies` in the `foo` package.\n
-        `build_dependencies` is ignored and not recommended for use in the future"
-        )
-        .run();
-}
-
-#[cargo_test]
-fn lib_crate_types_conflicting_warning() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.5.0"
-                edition = "2015"
-                authors = ["wycats@example.com"]
-
-                [lib]
-                name = "foo"
-                crate-type = ["rlib", "dylib"]
-                crate_type = ["staticlib", "dylib"]
-            "#,
-        )
-        .file("src/lib.rs", "pub fn foo() {}")
-        .build();
-    p.cargo("build")
-        .with_stderr_contains(
-"[WARNING] conflicting between `crate-type` and `crate_type` in the `foo` library target.\n
-        `crate_type` is ignored and not recommended for use in the future",
-        )
-        .run();
-}
-
-#[cargo_test]
-fn examples_crate_types_conflicting_warning() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.5.0"
-                edition = "2015"
-                authors = ["wycats@example.com"]
-
-                [[example]]
-                name = "ex"
-                path = "examples/ex.rs"
-                crate-type = ["rlib", "dylib"]
-                crate_type = ["proc_macro"]
-                [[example]]
-                name = "goodbye"
-                path = "examples/ex-goodbye.rs"
-                crate-type = ["rlib", "dylib"]
-                crate_type = ["rlib", "staticlib"]
-            "#,
-        )
-        .file("src/lib.rs", "")
-        .file(
-            "examples/ex.rs",
-            r#"
-                fn main() { println!("ex"); }
-            "#,
-        )
-        .file(
-            "examples/ex-goodbye.rs",
-            r#"
-                fn main() { println!("goodbye"); }
-            "#,
-        )
-        .build();
-    p.cargo("build")
-        .with_stderr_contains(
-            "\
-[WARNING] conflicting between `crate-type` and `crate_type` in the `ex` example target.\n
-        `crate_type` is ignored and not recommended for use in the future
-[WARNING] conflicting between `crate-type` and `crate_type` in the `goodbye` example target.\n
-        `crate_type` is ignored and not recommended for use in the future",
-        )
-        .run();
-}
-
 #[cargo_test]
 fn self_dependency() {
     let p = project()
@@ -2521,7 +2370,7 @@ fn verbose_release_build_deps() {
 
                 [lib]
                 name = "foo"
-                crate_type = ["dylib", "rlib"]
+                crate-type = ["dylib", "rlib"]
             "#,
         )
         .file("foo/src/lib.rs", "")
@@ -3506,90 +3355,6 @@ fn cargo_platform_specific_dependency() {
     p.cargo("test").run();
 }
 
-#[cargo_test]
-fn cargo_platform_specific_dependency_build_dependencies_conflicting_warning() {
-    let host = rustc_host();
-    let p = project()
-        .file(
-            "Cargo.toml",
-            &format!(
-                r#"
-                    [package]
-                    name = "foo"
-                    version = "0.5.0"
-                    edition = "2015"
-                    authors = ["wycats@example.com"]
-                    build = "build.rs"
-
-                    [target.{host}.build-dependencies]
-                    build = {{ path = "build" }}
-                    [target.{host}.build_dependencies]
-                    build = {{ path = "build" }}
-                "#,
-                host = host
-            ),
-        )
-        .file("src/main.rs", "fn main() { }")
-        .file(
-            "build.rs",
-            "extern crate build; fn main() { build::build(); }",
-        )
-        .file("build/Cargo.toml", &basic_manifest("build", "0.5.0"))
-        .file("build/src/lib.rs", "pub fn build() {}")
-        .build();
-
-    p.cargo("build")
-        .with_stderr_contains(
-        format!("[WARNING] conflicting between `build-dependencies` and `build_dependencies` in the `{}` platform target.\n
-        `build_dependencies` is ignored and not recommended for use in the future", host)
-        )
-        .run();
-
-    assert!(p.bin("foo").is_file());
-}
-
-#[cargo_test]
-fn cargo_platform_specific_dependency_dev_dependencies_conflicting_warning() {
-    let host = rustc_host();
-    let p = project()
-        .file(
-            "Cargo.toml",
-            &format!(
-                r#"
-                    [package]
-                    name = "foo"
-                    version = "0.5.0"
-                    edition = "2015"
-                    authors = ["wycats@example.com"]
-
-                    [target.{host}.dev-dependencies]
-                    dev = {{ path = "dev" }}
-                    [target.{host}.dev_dependencies]
-                    dev = {{ path = "dev" }}
-                "#,
-                host = host
-            ),
-        )
-        .file("src/main.rs", "fn main() { }")
-        .file(
-            "tests/foo.rs",
-            "extern crate dev; #[test] fn foo() { dev::dev() }",
-        )
-        .file("dev/Cargo.toml", &basic_manifest("dev", "0.5.0"))
-        .file("dev/src/lib.rs", "pub fn dev() {}")
-        .build();
-
-    p.cargo("build")
-        .with_stderr_contains(
-        format!("[WARNING] conflicting between `dev-dependencies` and `dev_dependencies` in the `{}` platform target.\n
-        `dev_dependencies` is ignored and not recommended for use in the future", host)
-        )
-        .run();
-
-    assert!(p.bin("foo").is_file());
-    p.cargo("test").run();
-}
-
 #[cargo_test]
 fn bad_platform_specific_dependency() {
     let p = project()
diff --git a/tests/testsuite/cross_compile.rs b/tests/testsuite/cross_compile.rs
index f55e5992024..bcb0a419017 100644
--- a/tests/testsuite/cross_compile.rs
+++ b/tests/testsuite/cross_compile.rs
@@ -1175,7 +1175,7 @@ fn cross_test_dylib() {
 
                 [lib]
                 name = "foo"
-                crate_type = ["dylib"]
+                crate-type = ["dylib"]
 
                 [dependencies.bar]
                 path = "bar"
@@ -1212,7 +1212,7 @@ fn cross_test_dylib() {
 
                 [lib]
                 name = "bar"
-                crate_type = ["dylib"]
+                crate-type = ["dylib"]
             "#,
         )
         .file(
diff --git a/tests/testsuite/features.rs b/tests/testsuite/features.rs
index 72957b0771c..0b83f31af2e 100644
--- a/tests/testsuite/features.rs
+++ b/tests/testsuite/features.rs
@@ -2204,45 +2204,3 @@ fn invalid_feature_name_slash_error() {
         )
         .run();
 }
-
-#[cargo_test]
-fn default_features_conflicting_warning() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.1.0"
-                edition = "2015"
-                authors = []
-
-                [dependencies]
-                a = { path = "a", features = ["f1"], default-features = false, default_features = false }
-            "#,
-        )
-        .file("src/lib.rs", "")
-        .file(
-            "a/Cargo.toml",
-            r#"
-                [package]
-                name = "a"
-                version = "0.1.0"
-                edition = "2015"
-                authors = []
-
-                [features]
-                default = ["f1"]
-                f1 = []
-            "#,
-        )
-        .file("a/src/lib.rs", "")
-        .build();
-
-    p.cargo("check")
-        .with_stderr_contains(
-"[WARNING] conflicting between `default-features` and `default_features` in the `a` dependency.\n
-        `default_features` is ignored and not recommended for use in the future"
-        )
-        .run();
-}
diff --git a/tests/testsuite/proc_macro.rs b/tests/testsuite/proc_macro.rs
index 1f6a378c11d..86bfe086c99 100644
--- a/tests/testsuite/proc_macro.rs
+++ b/tests/testsuite/proc_macro.rs
@@ -345,32 +345,6 @@ fn proc_macro_crate_type_warning() {
         .run();
 }
 
-#[cargo_test]
-fn proc_macro_conflicting_warning() {
-    let foo = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.1.0"
-                edition = "2015"
-                [lib]
-                proc-macro = false
-                proc_macro = true
-            "#,
-        )
-        .file("src/lib.rs", "")
-        .build();
-
-    foo.cargo("check")
-        .with_stderr_contains(
-"[WARNING] conflicting between `proc-macro` and `proc_macro` in the `foo` library target.\n
-        `proc_macro` is ignored and not recommended for use in the future",
-        )
-        .run();
-}
-
 #[cargo_test]
 fn proc_macro_crate_type_warning_plugin() {
     let foo = project()
@@ -509,7 +483,7 @@ fn proc_macro_built_once() {
                 edition = "2015"
 
                 [lib]
-                proc_macro = true
+                proc-macro = true
 
                 [features]
                 a = []
diff --git a/tests/testsuite/profiles.rs b/tests/testsuite/profiles.rs
index d04cdacd5b2..8348ffd034c 100644
--- a/tests/testsuite/profiles.rs
+++ b/tests/testsuite/profiles.rs
@@ -203,7 +203,7 @@ fn top_level_overrides_deps() {
 
                 [lib]
                 name = "foo"
-                crate_type = ["dylib", "rlib"]
+                crate-type = ["dylib", "rlib"]
             "#,
         )
         .file("foo/src/lib.rs", "")
diff --git a/tests/testsuite/run.rs b/tests/testsuite/run.rs
index ac7707985ea..15ca5591ca2 100644
--- a/tests/testsuite/run.rs
+++ b/tests/testsuite/run.rs
@@ -443,7 +443,7 @@ fn run_library_example() {
                 authors = []
                 [[example]]
                 name = "bar"
-                crate_type = ["lib"]
+                crate-type = ["lib"]
             "#,
         )
         .file("src/lib.rs", "")
@@ -468,7 +468,7 @@ fn run_bin_example() {
                 edition = "2015"
                 [[example]]
                 name = "bar"
-                crate_type = ["bin"]
+                crate-type = ["bin"]
             "#,
         )
         .file("src/lib.rs", "")
diff --git a/tests/testsuite/test.rs b/tests/testsuite/test.rs
index b0ca38670fc..a32cb6d0eba 100644
--- a/tests/testsuite/test.rs
+++ b/tests/testsuite/test.rs
@@ -1330,7 +1330,7 @@ fn test_dylib() {
 
                 [lib]
                 name = "foo"
-                crate_type = ["dylib"]
+                crate-type = ["dylib"]
 
                 [dependencies.bar]
                 path = "bar"
@@ -1367,7 +1367,7 @@ fn test_dylib() {
 
                 [lib]
                 name = "bar"
-                crate_type = ["dylib"]
+                crate-type = ["dylib"]
             "#,
         )
         .file("bar/src/lib.rs", "pub fn baz() {}")