diff --git a/tests/testsuite/build.rs b/tests/testsuite/build.rs
index dd67161d6..176ec706d 100644
--- a/tests/testsuite/build.rs
+++ b/tests/testsuite/build.rs
@@ -4161,7 +4161,7 @@ fn compiler_json_error_format() {
         )
         .file(
             "build.rs",
-            "fn main() { println!(\"cargo:rustc-cfg=xyz\") }",
+            "fn main() { println!(\"cargo::rustc-cfg=xyz\") }",
         )
         .file("src/main.rs", "fn main() { let unused = 92; }")
         .file("bar/Cargo.toml", &basic_manifest("bar", "0.5.0"))
@@ -5314,11 +5314,11 @@ fn deterministic_cfg_flags() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-cfg=cfg_a");
-                    println!("cargo:rustc-cfg=cfg_b");
-                    println!("cargo:rustc-cfg=cfg_c");
-                    println!("cargo:rustc-cfg=cfg_d");
-                    println!("cargo:rustc-cfg=cfg_e");
+                    println!("cargo::rustc-cfg=cfg_a");
+                    println!("cargo::rustc-cfg=cfg_b");
+                    println!("cargo::rustc-cfg=cfg_c");
+                    println!("cargo::rustc-cfg=cfg_d");
+                    println!("cargo::rustc-cfg=cfg_e");
                 }
             "#,
         )
diff --git a/tests/testsuite/build_script_env.rs b/tests/testsuite/build_script_env.rs
index 5220506a7..94c096124 100644
--- a/tests/testsuite/build_script_env.rs
+++ b/tests/testsuite/build_script_env.rs
@@ -12,7 +12,7 @@ fn rerun_if_env_changes() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rerun-if-env-changed=FOO");
+                    println!("cargo::rerun-if-env-changed=FOO");
                 }
             "#,
         )
@@ -66,8 +66,8 @@ fn rerun_if_env_or_file_changes() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rerun-if-env-changed=FOO");
-                    println!("cargo:rerun-if-changed=foo");
+                    println!("cargo::rerun-if-env-changed=FOO");
+                    println!("cargo::rerun-if-changed=foo");
                 }
             "#,
         )
@@ -112,7 +112,7 @@ fn rerun_if_env_or_file_changes() {
 fn rustc_bootstrap() {
     let build_rs = r#"
         fn main() {
-            println!("cargo:rustc-env=RUSTC_BOOTSTRAP=1");
+            println!("cargo::rustc-env=RUSTC_BOOTSTRAP=1");
         }
     "#;
     let p = project()
diff --git a/tests/testsuite/build_script_extra_link_arg.rs b/tests/testsuite/build_script_extra_link_arg.rs
index 964a55e97..49c33d979 100644
--- a/tests/testsuite/build_script_extra_link_arg.rs
+++ b/tests/testsuite/build_script_extra_link_arg.rs
@@ -16,7 +16,7 @@ fn build_script_extra_link_arg_bin() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg-bins=--this-is-a-bogus-flag");
+                    println!("cargo::rustc-link-arg-bins=--this-is-a-bogus-flag");
                 }
             "#,
         )
@@ -53,9 +53,9 @@ fn build_script_extra_link_arg_bin_single() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg-bins=--bogus-flag-all");
-                    println!("cargo:rustc-link-arg-bin=foo=--bogus-flag-foo");
-                    println!("cargo:rustc-link-arg-bin=bar=--bogus-flag-bar");
+                    println!("cargo::rustc-link-arg-bins=--bogus-flag-all");
+                    println!("cargo::rustc-link-arg-bin=foo=--bogus-flag-foo");
+                    println!("cargo::rustc-link-arg-bin=bar=--bogus-flag-bar");
                 }
             "#,
         )
@@ -81,7 +81,7 @@ fn build_script_extra_link_arg() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg=--this-is-a-bogus-flag");
+                    println!("cargo::rustc-link-arg=--this-is-a-bogus-flag");
                 }
             "#,
         )
@@ -102,7 +102,7 @@ fn link_arg_missing_target() {
         .file("src/lib.rs", "")
         .file(
             "build.rs",
-            r#"fn main() { println!("cargo:rustc-link-arg-cdylib=--bogus"); }"#,
+            r#"fn main() { println!("cargo::rustc-link-arg-cdylib=--bogus"); }"#,
         )
         .build();
 
@@ -112,28 +112,28 @@ fn link_arg_missing_target() {
     //         .with_status(101)
     //         .with_stderr("\
     // [COMPILING] foo [..]
-    // error: invalid instruction `cargo:rustc-link-arg-cdylib` from build script of `foo v0.0.1 ([ROOT]/foo)`
+    // error: invalid instruction `cargo::rustc-link-arg-cdylib` from build script of `foo v0.0.1 ([ROOT]/foo)`
     // The package foo v0.0.1 ([ROOT]/foo) does not have a cdylib target.
     // ")
     //         .run();
 
     p.change_file(
         "build.rs",
-        r#"fn main() { println!("cargo:rustc-link-arg-bins=--bogus"); }"#,
+        r#"fn main() { println!("cargo::rustc-link-arg-bins=--bogus"); }"#,
     );
 
     p.cargo("check")
         .with_status(101)
         .with_stderr("\
 [COMPILING] foo [..]
-error: invalid instruction `cargo:rustc-link-arg-bins` from build script of `foo v0.0.1 ([ROOT]/foo)`
+error: invalid instruction `cargo::rustc-link-arg-bins` from build script of `foo v0.0.1 ([ROOT]/foo)`
 The package foo v0.0.1 ([ROOT]/foo) does not have a bin target.
 ")
         .run();
 
     p.change_file(
         "build.rs",
-        r#"fn main() { println!("cargo:rustc-link-arg-bin=abc=--bogus"); }"#,
+        r#"fn main() { println!("cargo::rustc-link-arg-bin=abc=--bogus"); }"#,
     );
 
     p.cargo("check")
@@ -141,7 +141,7 @@ The package foo v0.0.1 ([ROOT]/foo) does not have a bin target.
         .with_stderr(
             "\
 [COMPILING] foo [..]
-error: invalid instruction `cargo:rustc-link-arg-bin` from build script of `foo v0.0.1 ([ROOT]/foo)`
+error: invalid instruction `cargo::rustc-link-arg-bin` from build script of `foo v0.0.1 ([ROOT]/foo)`
 The package foo v0.0.1 ([ROOT]/foo) does not have a bin target with the name `abc`.
 ",
         )
@@ -149,7 +149,7 @@ The package foo v0.0.1 ([ROOT]/foo) does not have a bin target with the name `ab
 
     p.change_file(
         "build.rs",
-        r#"fn main() { println!("cargo:rustc-link-arg-bin=abc"); }"#,
+        r#"fn main() { println!("cargo::rustc-link-arg-bin=abc"); }"#,
     );
 
     p.cargo("check")
@@ -157,8 +157,8 @@ The package foo v0.0.1 ([ROOT]/foo) does not have a bin target with the name `ab
         .with_stderr(
             "\
 [COMPILING] foo [..]
-error: invalid instruction `cargo:rustc-link-arg-bin=abc` from build script of `foo v0.0.1 ([ROOT]/foo)`
-The instruction should have the form cargo:rustc-link-arg-bin=BIN=ARG
+error: invalid instruction `cargo::rustc-link-arg-bin=abc` from build script of `foo v0.0.1 ([ROOT]/foo)`
+The instruction should have the form cargo::rustc-link-arg-bin=BIN=ARG
 ",
         )
         .run();
@@ -192,7 +192,7 @@ fn cdylib_link_arg_transitive() {
             "bar/build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg-cdylib=--bogus");
+                    println!("cargo::rustc-link-arg-cdylib=--bogus");
                 }
             "#,
         )
@@ -204,7 +204,7 @@ fn cdylib_link_arg_transitive() {
 [COMPILING] bar v1.0.0 [..]
 [RUNNING] `rustc --crate-name build_script_build bar/build.rs [..]
 [RUNNING] `[..]build-script-build[..]
-warning: bar@1.0.0: cargo:rustc-link-arg-cdylib was specified in the build script of bar v1.0.0 \
+warning: bar@1.0.0: cargo::rustc-link-arg-cdylib was specified in the build script of bar v1.0.0 \
 ([ROOT]/foo/bar), but that package does not contain a cdylib target
 
 Allowing this was an unintended change in the 1.50 release, and may become an error in \
@@ -230,7 +230,7 @@ fn link_arg_transitive_not_allowed() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg=--bogus");
+                    println!("cargo::rustc-link-arg=--bogus");
                 }
             "#,
         )
@@ -289,7 +289,7 @@ fn link_arg_with_doctest() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg=--this-is-a-bogus-flag");
+                    println!("cargo::rustc-link-arg=--this-is-a-bogus-flag");
                 }
             "#,
         )
@@ -313,7 +313,7 @@ fn build_script_extra_link_arg_tests() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg-tests=--this-is-a-bogus-flag");
+                    println!("cargo::rustc-link-arg-tests=--this-is-a-bogus-flag");
                 }
             "#,
         )
@@ -337,7 +337,7 @@ fn build_script_extra_link_arg_benches() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg-benches=--this-is-a-bogus-flag");
+                    println!("cargo::rustc-link-arg-benches=--this-is-a-bogus-flag");
                 }
             "#,
         )
@@ -361,7 +361,7 @@ fn build_script_extra_link_arg_examples() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-link-arg-examples=--this-is-a-bogus-flag");
+                    println!("cargo::rustc-link-arg-examples=--this-is-a-bogus-flag");
                 }
             "#,
         )
diff --git a/tests/testsuite/check_cfg.rs b/tests/testsuite/check_cfg.rs
index 5a0ad7905..195dcf588 100644
--- a/tests/testsuite/check_cfg.rs
+++ b/tests/testsuite/check_cfg.rs
@@ -343,7 +343,7 @@ fn build_script_feedback() {
         .file("src/main.rs", "fn main() {}")
         .file(
             "build.rs",
-            r#"fn main() { println!("cargo:rustc-check-cfg=cfg(foo)"); }"#,
+            r#"fn main() { println!("cargo::rustc-check-cfg=cfg(foo)"); }"#,
         )
         .build();
 
@@ -369,7 +369,7 @@ fn build_script_doc() {
         .file("src/main.rs", "fn main() {}")
         .file(
             "build.rs",
-            r#"fn main() { println!("cargo:rustc-check-cfg=cfg(foo)"); }"#,
+            r#"fn main() { println!("cargo::rustc-check-cfg=cfg(foo)"); }"#,
         )
         .build();
 
@@ -478,8 +478,8 @@ fn build_script_test() {
         .file(
             "build.rs",
             r#"fn main() {
-                println!("cargo:rustc-check-cfg=cfg(foo)");
-                println!("cargo:rustc-cfg=foo");
+                println!("cargo::rustc-check-cfg=cfg(foo)");
+                println!("cargo::rustc-cfg=foo");
             }"#,
         )
         .file(
diff --git a/tests/testsuite/cross_compile.rs b/tests/testsuite/cross_compile.rs
index b57ba2c7a..32c1a4bf5 100644
--- a/tests/testsuite/cross_compile.rs
+++ b/tests/testsuite/cross_compile.rs
@@ -721,7 +721,7 @@ fn build_script_needed_for_host_and_target() {
                 use std::env;
                 fn main() {
                     let target = env::var("TARGET").unwrap();
-                    println!("cargo:rustc-flags=-L /path/to/{}", target);
+                    println!("cargo::rustc-flags=-L /path/to/{}", target);
                 }
             "#,
         )
@@ -1098,7 +1098,10 @@ fn platform_specific_variables_reflected_in_build_scripts() {
                 build = "build.rs"
             "#,
         )
-        .file("d1/build.rs", r#"fn main() { println!("cargo:val=1") }"#)
+        .file(
+            "d1/build.rs",
+            r#"fn main() { println!("cargo::metadata=val=1") }"#,
+        )
         .file("d1/src/lib.rs", "")
         .file(
             "d2/Cargo.toml",
@@ -1111,7 +1114,10 @@ fn platform_specific_variables_reflected_in_build_scripts() {
                 build = "build.rs"
             "#,
         )
-        .file("d2/build.rs", r#"fn main() { println!("cargo:val=1") }"#)
+        .file(
+            "d2/build.rs",
+            r#"fn main() { println!("cargo::metadata=val=1") }"#,
+        )
         .file("d2/src/lib.rs", "")
         .build();
 
diff --git a/tests/testsuite/dep_info.rs b/tests/testsuite/dep_info.rs
index e9ea47792..4741ebd2b 100644
--- a/tests/testsuite/dep_info.rs
+++ b/tests/testsuite/dep_info.rs
@@ -570,7 +570,7 @@ fn non_local_build_script() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rerun-if-changed=build.rs");
+                    println!("cargo::rerun-if-changed=build.rs");
                 }
             "#,
         )
diff --git a/tests/testsuite/doc.rs b/tests/testsuite/doc.rs
index 37dd47d76..c80f23d91 100644
--- a/tests/testsuite/doc.rs
+++ b/tests/testsuite/doc.rs
@@ -1021,7 +1021,7 @@ fn features() {
             "bar/build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-cfg=bar");
+                    println!("cargo::rustc-cfg=bar");
                 }
             "#,
         )
diff --git a/tests/testsuite/features2.rs b/tests/testsuite/features2.rs
index 125a293a0..29516d8ec 100644
--- a/tests/testsuite/features2.rs
+++ b/tests/testsuite/features2.rs
@@ -494,7 +494,7 @@ fn build_script_runtime_features() {
                 if is_set("CARGO_FEATURE_BUILD") {
                     res |= 4;
                 }
-                println!("cargo:rustc-cfg=RunCustomBuild=\"{}\"", res);
+                println!("cargo::rustc-cfg=RunCustomBuild=\"{}\"", res);
 
                 let mut res = 0;
                 if cfg!(feature = "normal") {
@@ -506,7 +506,7 @@ fn build_script_runtime_features() {
                 if cfg!(feature = "build") {
                     res |= 4;
                 }
-                println!("cargo:rustc-cfg=CustomBuild=\"{}\"", res);
+                println!("cargo::rustc-cfg=CustomBuild=\"{}\"", res);
             }
             "#,
         )
@@ -562,7 +562,7 @@ fn build_script_runtime_features() {
             r#"
             fn main() {
                 assert_eq!(common::foo(), common::build_time());
-                println!("cargo:rustc-cfg=from_build=\"{}\"", common::foo());
+                println!("cargo::rustc-cfg=from_build=\"{}\"", common::foo());
             }
             "#,
         )
@@ -1792,8 +1792,8 @@ fn shared_dep_same_but_dependencies() {
             "subdep/src/lib.rs",
             r#"
                 pub fn feat_func() {
-                    #[cfg(feature = "feat")] println!("cargo:warning=feat: enabled");
-                    #[cfg(not(feature = "feat"))] println!("cargo:warning=feat: not enabled");
+                    #[cfg(feature = "feat")] println!("cargo::warning=feat: enabled");
+                    #[cfg(not(feature = "feat"))] println!("cargo::warning=feat: not enabled");
                 }
             "#,
         )
@@ -1813,7 +1813,7 @@ warning: bin2@0.1.0: feat: enabled
         )
         .run();
     p.process(p.bin("bin1"))
-        .with_stdout("cargo:warning=feat: not enabled")
+        .with_stdout("cargo::warning=feat: not enabled")
         .run();
 
     // Make sure everything stays cached.
diff --git a/tests/testsuite/freshness.rs b/tests/testsuite/freshness.rs
index 2d9b3df68..1f81b544c 100644
--- a/tests/testsuite/freshness.rs
+++ b/tests/testsuite/freshness.rs
@@ -658,7 +658,7 @@ fn rerun_if_changed_in_dep() {
             "a/build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rerun-if-changed=build.rs");
+                    println!("cargo::rerun-if-changed=build.rs");
                 }
             "#,
         )
@@ -1730,8 +1730,8 @@ fn dirty_both_lib_and_test() {
                             .success(),
                         "slib build failed"
                     );
-                    println!("cargo:rustc-link-lib=slib");
-                    println!("cargo:rustc-link-search={}", out_dir.display());
+                    println!("cargo::rustc-link-lib=slib");
+                    println!("cargo::rustc-link-search={}", out_dir.display());
                 }
             "#,
         )
@@ -1772,7 +1772,7 @@ fn script_fails_stay_dirty() {
             r#"
                 mod helper;
                 fn main() {
-                    println!("cargo:rerun-if-changed=build.rs");
+                    println!("cargo::rerun-if-changed=build.rs");
                     helper::doit();
                 }
             "#,
@@ -1810,7 +1810,7 @@ fn simulated_docker_deps_stay_cached() {
             "build.rs",
             r#"
             fn main() {
-                println!("cargo:rerun-if-env-changed=SOMEVAR");
+                println!("cargo::rerun-if-env-changed=SOMEVAR");
             }
             "#,
         )
@@ -1821,7 +1821,7 @@ fn simulated_docker_deps_stay_cached() {
             "build.rs",
             r#"
             fn main() {
-                println!("cargo:rerun-if-changed=build.rs");
+                println!("cargo::rerun-if-changed=build.rs");
             }
             "#,
         )
@@ -2107,7 +2107,7 @@ fn move_target_directory_with_path_deps() {
                 use std::path::Path;
 
                 fn main() {
-                    println!("cargo:rerun-if-changed=build.rs");
+                    println!("cargo::rerun-if-changed=build.rs");
                     let out_dir = env::var("OUT_DIR").unwrap();
                     let dest_path = Path::new(&out_dir).join("hello.rs");
                     fs::write(&dest_path, r#"
@@ -2148,9 +2148,9 @@ fn rerun_if_changes() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rerun-if-env-changed=FOO");
+                    println!("cargo::rerun-if-env-changed=FOO");
                     if std::env::var("FOO").is_ok() {
-                        println!("cargo:rerun-if-env-changed=BAR");
+                        println!("cargo::rerun-if-env-changed=BAR");
                     }
                 }
             "#,
@@ -2648,7 +2648,7 @@ fn env_build_script_no_rebuild() {
             "build.rs",
             r#"
                 fn main() {
-                    println!("cargo:rustc-env=FOO=bar");
+                    println!("cargo::rustc-env=FOO=bar");
                 }
             "#,
         )
diff --git a/tests/testsuite/profile_overrides.rs b/tests/testsuite/profile_overrides.rs
index 65d9f3b51..eda34ad34 100644
--- a/tests/testsuite/profile_overrides.rs
+++ b/tests/testsuite/profile_overrides.rs
@@ -502,9 +502,9 @@ fn build_override_shared() {
             r#"
             fn main() {
                 if std::env::var("DEBUG").unwrap() != "false" {
-                    println!("cargo:rustc-cfg=foo_debug");
+                    println!("cargo::rustc-cfg=foo_debug");
                 } else {
-                    println!("cargo:rustc-cfg=foo_release");
+                    println!("cargo::rustc-cfg=foo_release");
                 }
             }
             "#,
diff --git a/tests/testsuite/run.rs b/tests/testsuite/run.rs
index c7ddd5d9e..4537b2caa 100644
--- a/tests/testsuite/run.rs
+++ b/tests/testsuite/run.rs
@@ -1202,8 +1202,8 @@ fn run_with_library_paths() {
             &format!(
                 r##"
                     fn main() {{
-                        println!(r#"cargo:rustc-link-search=native={}"#);
-                        println!(r#"cargo:rustc-link-search={}"#);
+                        println!(r#"cargo::rustc-link-search=native={}"#);
+                        println!(r#"cargo::rustc-link-search={}"#);
                     }}
                 "##,
                 dir1.display(),
@@ -1261,9 +1261,9 @@ fn library_paths_sorted_alphabetically() {
             &format!(
                 r##"
                     fn main() {{
-                        println!(r#"cargo:rustc-link-search=native={}"#);
-                        println!(r#"cargo:rustc-link-search=native={}"#);
-                        println!(r#"cargo:rustc-link-search=native={}"#);
+                        println!(r#"cargo::rustc-link-search=native={}"#);
+                        println!(r#"cargo::rustc-link-search=native={}"#);
+                        println!(r#"cargo::rustc-link-search=native={}"#);
                     }}
                 "##,
                 dir1.display(),
@@ -1535,8 +1535,8 @@ fn run_link_system_path_macos() {
             &format!(
                 r#"
                 fn main() {{
-                    println!("cargo:rustc-link-lib=foo");
-                    println!("cargo:rustc-link-search={}");
+                    println!("cargo::rustc-link-lib=foo");
+                    println!("cargo::rustc-link-search={}");
                 }}
                 "#,
                 p.target_debug_dir().display()
diff --git a/tests/testsuite/warn_on_failure.rs b/tests/testsuite/warn_on_failure.rs
index f2c2bb071..110364c83 100644
--- a/tests/testsuite/warn_on_failure.rs
+++ b/tests/testsuite/warn_on_failure.rs
@@ -24,10 +24,10 @@ fn make_lib(lib_src: &str) {
                 r#"
                     fn main() {{
                         use std::io::Write;
-                        println!("cargo:warning={{}}", "{}");
+                        println!("cargo::warning={{}}", "{}");
                         println!("hidden stdout");
                         write!(&mut ::std::io::stderr(), "hidden stderr");
-                        println!("cargo:warning={{}}", "{}");
+                        println!("cargo::warning={{}}", "{}");
                     }}
                 "#,
                 WARNING1, WARNING2