diff --git a/crates/cargo-test-support/src/lib.rs b/crates/cargo-test-support/src/lib.rs
index e334041a0..0fe3b96c3 100644
--- a/crates/cargo-test-support/src/lib.rs
+++ b/crates/cargo-test-support/src/lib.rs
@@ -13,7 +13,6 @@ use std::fs;
 use std::os;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Output};
-use std::str;
 use std::sync::OnceLock;
 use std::thread::JoinHandle;
 use std::time::{self, Duration};
@@ -36,6 +35,7 @@ macro_rules! t {
 
 pub use snapbox::file;
 pub use snapbox::path::current_dir;
+pub use snapbox::str;
 
 #[track_caller]
 pub fn panic_error(what: &str, err: impl Into<anyhow::Error>) -> ! {
@@ -972,8 +972,8 @@ impl Execs {
 
     fn match_output(&self, code: Option<i32>, stdout: &[u8], stderr: &[u8]) -> Result<()> {
         self.verify_checks_output(stdout, stderr);
-        let stdout = str::from_utf8(stdout).expect("stdout is not utf8");
-        let stderr = str::from_utf8(stderr).expect("stderr is not utf8");
+        let stdout = std::str::from_utf8(stdout).expect("stdout is not utf8");
+        let stderr = std::str::from_utf8(stderr).expect("stderr is not utf8");
         let cwd = self.get_cwd();
 
         match self.expect_exit_code {
@@ -1211,7 +1211,7 @@ pub trait TestEnv: Sized {
                     .exec_with_output()
                 {
                     Ok(output) => {
-                        let s = str::from_utf8(&output.stdout).expect("utf8").trim();
+                        let s = std::str::from_utf8(&output.stdout).expect("utf8").trim();
                         let mut p = PathBuf::from(s);
                         p.pop();
                         p
diff --git a/tests/testsuite/cargo/help/mod.rs b/tests/testsuite/cargo/help/mod.rs
index fcf53c959..e1ea0ae41 100644
--- a/tests/testsuite/cargo/help/mod.rs
+++ b/tests/testsuite/cargo/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -8,5 +9,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo/help/stderr.log b/tests/testsuite/cargo/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo/z_help/mod.rs b/tests/testsuite/cargo/z_help/mod.rs
index 43afd3853..8c7b2668f 100644
--- a/tests/testsuite/cargo/z_help/mod.rs
+++ b/tests/testsuite/cargo/z_help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo/z_help/stderr.log b/tests/testsuite/cargo/z_help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_add/help/mod.rs b/tests/testsuite/cargo_add/help/mod.rs
index 15f9a6a04..f7a9964ab 100644
--- a/tests/testsuite/cargo_add/help/mod.rs
+++ b/tests/testsuite/cargo_add/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_add/help/stderr.log b/tests/testsuite/cargo_add/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_add/quiet/mod.rs b/tests/testsuite/cargo_add/quiet/mod.rs
index c570aabd8..7c8f9fd3f 100644
--- a/tests/testsuite/cargo_add/quiet/mod.rs
+++ b/tests/testsuite/cargo_add/quiet/mod.rs
@@ -2,6 +2,7 @@ use cargo_test_support::compare::assert_ui;
 use cargo_test_support::current_dir;
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 use cargo_test_support::Project;
 
 #[cargo_test]
@@ -25,7 +26,7 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 
     assert_ui().subset_matches(current_dir!().join("out"), &project_root);
 }
diff --git a/tests/testsuite/cargo_add/quiet/stderr.log b/tests/testsuite/cargo_add/quiet/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_bench/help/mod.rs b/tests/testsuite/cargo_bench/help/mod.rs
index 104399937..d2b1737bb 100644
--- a/tests/testsuite/cargo_bench/help/mod.rs
+++ b/tests/testsuite/cargo_bench/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_bench/help/stderr.log b/tests/testsuite/cargo_bench/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_build/help/mod.rs b/tests/testsuite/cargo_build/help/mod.rs
index d1271bf1f..127fe424f 100644
--- a/tests/testsuite/cargo_build/help/mod.rs
+++ b/tests/testsuite/cargo_build/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_build/help/stderr.log b/tests/testsuite/cargo_build/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_check/help/mod.rs b/tests/testsuite/cargo_check/help/mod.rs
index 32d87803f..16c690c41 100644
--- a/tests/testsuite/cargo_check/help/mod.rs
+++ b/tests/testsuite/cargo_check/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_check/help/stderr.log b/tests/testsuite/cargo_check/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_clean/help/mod.rs b/tests/testsuite/cargo_clean/help/mod.rs
index d4efe3c36..533dc1337 100644
--- a/tests/testsuite/cargo_clean/help/mod.rs
+++ b/tests/testsuite/cargo_clean/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_clean/help/stderr.log b/tests/testsuite/cargo_clean/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_config/help/mod.rs b/tests/testsuite/cargo_config/help/mod.rs
index 20bcef683..000a80d9d 100644
--- a/tests/testsuite/cargo_config/help/mod.rs
+++ b/tests/testsuite/cargo_config/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_config/help/stderr.log b/tests/testsuite/cargo_config/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_doc/help/mod.rs b/tests/testsuite/cargo_doc/help/mod.rs
index 4fc28adba..4c33ea6e9 100644
--- a/tests/testsuite/cargo_doc/help/mod.rs
+++ b/tests/testsuite/cargo_doc/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_doc/help/stderr.log b/tests/testsuite/cargo_doc/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_fetch/help/mod.rs b/tests/testsuite/cargo_fetch/help/mod.rs
index b0f8349f0..e44d202c7 100644
--- a/tests/testsuite/cargo_fetch/help/mod.rs
+++ b/tests/testsuite/cargo_fetch/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_fetch/help/stderr.log b/tests/testsuite/cargo_fetch/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_fix/help/mod.rs b/tests/testsuite/cargo_fix/help/mod.rs
index 2a43ad544..bd849d5fc 100644
--- a/tests/testsuite/cargo_fix/help/mod.rs
+++ b/tests/testsuite/cargo_fix/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_fix/help/stderr.log b/tests/testsuite/cargo_fix/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_generate_lockfile/help/mod.rs b/tests/testsuite/cargo_generate_lockfile/help/mod.rs
index c22fb622f..7e5d87d66 100644
--- a/tests/testsuite/cargo_generate_lockfile/help/mod.rs
+++ b/tests/testsuite/cargo_generate_lockfile/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_generate_lockfile/help/stderr.log b/tests/testsuite/cargo_generate_lockfile/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_git_checkout/help/mod.rs b/tests/testsuite/cargo_git_checkout/help/mod.rs
index a11c97870..07f387069 100644
--- a/tests/testsuite/cargo_git_checkout/help/mod.rs
+++ b/tests/testsuite/cargo_git_checkout/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_git_checkout/help/stderr.log b/tests/testsuite/cargo_git_checkout/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_help/help/mod.rs b/tests/testsuite/cargo_help/help/mod.rs
index ef54d25b3..a8640b73c 100644
--- a/tests/testsuite/cargo_help/help/mod.rs
+++ b/tests/testsuite/cargo_help/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_help/help/stderr.log b/tests/testsuite/cargo_help/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_init/help/mod.rs b/tests/testsuite/cargo_init/help/mod.rs
index 58febefe8..87eec6886 100644
--- a/tests/testsuite/cargo_init/help/mod.rs
+++ b/tests/testsuite/cargo_init/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_init/help/stderr.log b/tests/testsuite/cargo_init/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_install/help/mod.rs b/tests/testsuite/cargo_install/help/mod.rs
index 9700da015..9aa299efd 100644
--- a/tests/testsuite/cargo_install/help/mod.rs
+++ b/tests/testsuite/cargo_install/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_install/help/stderr.log b/tests/testsuite/cargo_install/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_locate_project/help/mod.rs b/tests/testsuite/cargo_locate_project/help/mod.rs
index a1abcdb24..7c9a7b39d 100644
--- a/tests/testsuite/cargo_locate_project/help/mod.rs
+++ b/tests/testsuite/cargo_locate_project/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_locate_project/help/stderr.log b/tests/testsuite/cargo_locate_project/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_login/help/mod.rs b/tests/testsuite/cargo_login/help/mod.rs
index d36f4551f..94dfbb4f6 100644
--- a/tests/testsuite/cargo_login/help/mod.rs
+++ b/tests/testsuite/cargo_login/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_login/help/stderr.log b/tests/testsuite/cargo_login/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_logout/help/mod.rs b/tests/testsuite/cargo_logout/help/mod.rs
index a141c3c7d..76c643a1f 100644
--- a/tests/testsuite/cargo_logout/help/mod.rs
+++ b/tests/testsuite/cargo_logout/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_logout/help/stderr.log b/tests/testsuite/cargo_logout/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_metadata/help/mod.rs b/tests/testsuite/cargo_metadata/help/mod.rs
index 04d2e13a4..fe43d3557 100644
--- a/tests/testsuite/cargo_metadata/help/mod.rs
+++ b/tests/testsuite/cargo_metadata/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_metadata/help/stderr.log b/tests/testsuite/cargo_metadata/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_new/help/mod.rs b/tests/testsuite/cargo_new/help/mod.rs
index 0804f3890..e28338262 100644
--- a/tests/testsuite/cargo_new/help/mod.rs
+++ b/tests/testsuite/cargo_new/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_new/help/stderr.log b/tests/testsuite/cargo_new/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_owner/help/mod.rs b/tests/testsuite/cargo_owner/help/mod.rs
index 69ff5c455..b5e090aa9 100644
--- a/tests/testsuite/cargo_owner/help/mod.rs
+++ b/tests/testsuite/cargo_owner/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_owner/help/stderr.log b/tests/testsuite/cargo_owner/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_package/help/mod.rs b/tests/testsuite/cargo_package/help/mod.rs
index 10d1730e3..d31216514 100644
--- a/tests/testsuite/cargo_package/help/mod.rs
+++ b/tests/testsuite/cargo_package/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_package/help/stderr.log b/tests/testsuite/cargo_package/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_pkgid/help/mod.rs b/tests/testsuite/cargo_pkgid/help/mod.rs
index 9dea28b56..a7d3dd412 100644
--- a/tests/testsuite/cargo_pkgid/help/mod.rs
+++ b/tests/testsuite/cargo_pkgid/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_pkgid/help/stderr.log b/tests/testsuite/cargo_pkgid/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_publish/help/mod.rs b/tests/testsuite/cargo_publish/help/mod.rs
index 57d090afa..82b05e5df 100644
--- a/tests/testsuite/cargo_publish/help/mod.rs
+++ b/tests/testsuite/cargo_publish/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_publish/help/stderr.log b/tests/testsuite/cargo_publish/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_read_manifest/help/mod.rs b/tests/testsuite/cargo_read_manifest/help/mod.rs
index ef18fa6b6..5f66aed3a 100644
--- a/tests/testsuite/cargo_read_manifest/help/mod.rs
+++ b/tests/testsuite/cargo_read_manifest/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_read_manifest/help/stderr.log b/tests/testsuite/cargo_read_manifest/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_remove/help/mod.rs b/tests/testsuite/cargo_remove/help/mod.rs
index 6af5b4c3f..915b4cd5f 100644
--- a/tests/testsuite/cargo_remove/help/mod.rs
+++ b/tests/testsuite/cargo_remove/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_remove/help/stderr.log b/tests/testsuite/cargo_remove/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_report/help/mod.rs b/tests/testsuite/cargo_report/help/mod.rs
index 352216475..3318c1b3d 100644
--- a/tests/testsuite/cargo_report/help/mod.rs
+++ b/tests/testsuite/cargo_report/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_report/help/stderr.log b/tests/testsuite/cargo_report/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_run/help/mod.rs b/tests/testsuite/cargo_run/help/mod.rs
index fc2db8257..d7ce00600 100644
--- a/tests/testsuite/cargo_run/help/mod.rs
+++ b/tests/testsuite/cargo_run/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_run/help/stderr.log b/tests/testsuite/cargo_run/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_rustc/help/mod.rs b/tests/testsuite/cargo_rustc/help/mod.rs
index 9f95e5f10..921b48100 100644
--- a/tests/testsuite/cargo_rustc/help/mod.rs
+++ b/tests/testsuite/cargo_rustc/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_rustc/help/stderr.log b/tests/testsuite/cargo_rustc/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_rustdoc/help/mod.rs b/tests/testsuite/cargo_rustdoc/help/mod.rs
index bd6e2977e..78d61ae9b 100644
--- a/tests/testsuite/cargo_rustdoc/help/mod.rs
+++ b/tests/testsuite/cargo_rustdoc/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_rustdoc/help/stderr.log b/tests/testsuite/cargo_rustdoc/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_search/help/mod.rs b/tests/testsuite/cargo_search/help/mod.rs
index f8f78c52b..d25c9fb88 100644
--- a/tests/testsuite/cargo_search/help/mod.rs
+++ b/tests/testsuite/cargo_search/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_search/help/stderr.log b/tests/testsuite/cargo_search/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_test/help/mod.rs b/tests/testsuite/cargo_test/help/mod.rs
index 1a3cdf4ce..978abcd30 100644
--- a/tests/testsuite/cargo_test/help/mod.rs
+++ b/tests/testsuite/cargo_test/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_test/help/stderr.log b/tests/testsuite/cargo_test/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_tree/help/mod.rs b/tests/testsuite/cargo_tree/help/mod.rs
index d67582e6a..eed0a122c 100644
--- a/tests/testsuite/cargo_tree/help/mod.rs
+++ b/tests/testsuite/cargo_tree/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_tree/help/stderr.log b/tests/testsuite/cargo_tree/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_uninstall/help/mod.rs b/tests/testsuite/cargo_uninstall/help/mod.rs
index b32a378aa..0bcf73b78 100644
--- a/tests/testsuite/cargo_uninstall/help/mod.rs
+++ b/tests/testsuite/cargo_uninstall/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_uninstall/help/stderr.log b/tests/testsuite/cargo_uninstall/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_update/help/mod.rs b/tests/testsuite/cargo_update/help/mod.rs
index b3bc2146c..6b9872b20 100644
--- a/tests/testsuite/cargo_update/help/mod.rs
+++ b/tests/testsuite/cargo_update/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_update/help/stderr.log b/tests/testsuite/cargo_update/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_vendor/help/mod.rs b/tests/testsuite/cargo_vendor/help/mod.rs
index 1b4b53501..b31d90062 100644
--- a/tests/testsuite/cargo_vendor/help/mod.rs
+++ b/tests/testsuite/cargo_vendor/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_vendor/help/stderr.log b/tests/testsuite/cargo_vendor/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_verify_project/help/mod.rs b/tests/testsuite/cargo_verify_project/help/mod.rs
index b3f1ad689..0ba01a1a9 100644
--- a/tests/testsuite/cargo_verify_project/help/mod.rs
+++ b/tests/testsuite/cargo_verify_project/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_verify_project/help/stderr.log b/tests/testsuite/cargo_verify_project/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_version/help/mod.rs b/tests/testsuite/cargo_version/help/mod.rs
index 8520e0b0e..e1741364f 100644
--- a/tests/testsuite/cargo_version/help/mod.rs
+++ b/tests/testsuite/cargo_version/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_version/help/stderr.log b/tests/testsuite/cargo_version/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/testsuite/cargo_yank/help/mod.rs b/tests/testsuite/cargo_yank/help/mod.rs
index 9ea87f287..c64e97731 100644
--- a/tests/testsuite/cargo_yank/help/mod.rs
+++ b/tests/testsuite/cargo_yank/help/mod.rs
@@ -1,5 +1,6 @@
 use cargo_test_support::file;
 use cargo_test_support::prelude::*;
+use cargo_test_support::str;
 
 #[cargo_test]
 fn case() {
@@ -9,5 +10,5 @@ fn case() {
         .assert()
         .success()
         .stdout_matches(file!["stdout.log"])
-        .stderr_matches(file!["stderr.log"]);
+        .stderr_matches(str![""]);
 }
diff --git a/tests/testsuite/cargo_yank/help/stderr.log b/tests/testsuite/cargo_yank/help/stderr.log
deleted file mode 100644
index e69de29bb..000000000