From f4baeb54ddf222530f98db58f205e8f681198d3b Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Fri, 10 Sep 2021 09:40:37 -0700
Subject: [PATCH] Fix rustc --profile=dev unstable check.

---
 src/cargo/util/command_prelude.rs |  2 +-
 tests/testsuite/profile_custom.rs | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/cargo/util/command_prelude.rs b/src/cargo/util/command_prelude.rs
index c99b8688f1e..bab36a9a94d 100644
--- a/src/cargo/util/command_prelude.rs
+++ b/src/cargo/util/command_prelude.rs
@@ -363,7 +363,7 @@ pub trait ArgMatchesExt {
         // This is an early exit, since it allows combination with `--release`.
         match (specified_profile, profile_checking) {
             // `cargo rustc` has legacy handling of these names
-            (Some(name @ ("test" | "bench" | "check")), ProfileChecking::LegacyRustc) |
+            (Some(name @ ("dev" | "test" | "bench" | "check")), ProfileChecking::LegacyRustc) |
             // `cargo fix` and `cargo check` has legacy handling of this profile name
             (Some(name @ "test"), ProfileChecking::LegacyTestOnly) => return Ok(InternedString::new(name)),
             _ => {}
diff --git a/tests/testsuite/profile_custom.rs b/tests/testsuite/profile_custom.rs
index ff4064653f8..1307b4e071b 100644
--- a/tests/testsuite/profile_custom.rs
+++ b/tests/testsuite/profile_custom.rs
@@ -702,3 +702,32 @@ fn legacy_commands_support_custom() {
         p.build_dir().rm_rf();
     }
 }
+
+#[cargo_test]
+fn legacy_rustc() {
+    // `cargo rustc` historically has supported dev/test/bench/check
+    // other profiles are covered in check::rustc_check
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+
+                [profile.dev]
+                codegen-units = 3
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+    p.cargo("rustc --profile dev -v")
+        .with_stderr(
+            "\
+[COMPILING] foo v0.1.0 [..]
+[RUNNING] `rustc --crate-name foo [..]-C codegen-units=3[..]
+[FINISHED] [..]
+",
+        )
+        .run();
+}