From d17ccec2e8c06f1a9157424aee0bf89e8854a9de Mon Sep 17 00:00:00 2001
From: Hidehito Yabuuchi <hdht.ybuc@gmail.com>
Date: Sat, 23 Feb 2019 13:12:18 +0900
Subject: [PATCH 1/3] Warn on misspelled env vars 'RUST_FLAGS' and
 'RUSTDOC_FLAGS'

---
 src/cargo/ops/cargo_compile.rs | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/cargo/ops/cargo_compile.rs b/src/cargo/ops/cargo_compile.rs
index 169fcaab9a5..fbfe62b0470 100644
--- a/src/cargo/ops/cargo_compile.rs
+++ b/src/cargo/ops/cargo_compile.rs
@@ -245,6 +245,27 @@ pub fn compile_ws<'a>(
         ref export_dir,
     } = *options;
 
+    match build_config.mode {
+        CompileMode::Test
+        | CompileMode::Build
+        | CompileMode::Check { .. }
+        | CompileMode::Bench
+        | CompileMode::RunCustomBuild => {
+            if std::env::var("RUST_FLAGS").is_ok() {
+                config.shell().warn(
+                    "Cargo does not read `RUST_FLAGS` environment variable. Did you mean `RUSTFLAGS`?",
+                )?;
+            }
+        }
+        CompileMode::Doc { .. } | CompileMode::Doctest => {
+            if std::env::var("RUSTDOC_FLAGS").is_ok() {
+                config.shell().warn(
+                    "Cargo does not read `RUSTDOC_FLAGS` environment variable. Did you mean `RUSTDOCFLAGS`?"
+                )?;
+            }
+        }
+    }
+
     let default_arch_kind = if build_config.requested_target.is_some() {
         Kind::Target
     } else {

From 44aec50e4ed60a35b9a7612022a1f781bcb786d0 Mon Sep 17 00:00:00 2001
From: Hidehito Yabuuchi <hdht.ybuc@gmail.com>
Date: Sat, 23 Feb 2019 17:07:59 +0900
Subject: [PATCH 2/3] Add tests for warning on misspelled env vars

---
 tests/testsuite/rustdocflags.rs | 10 ++++++++++
 tests/testsuite/rustflags.rs    | 34 +++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/tests/testsuite/rustdocflags.rs b/tests/testsuite/rustdocflags.rs
index 7ac963da710..b429a7cebac 100644
--- a/tests/testsuite/rustdocflags.rs
+++ b/tests/testsuite/rustdocflags.rs
@@ -85,3 +85,13 @@ fn rustdocflags_passed_to_rustdoc_through_cargo_test_only_once() {
         .env("RUSTDOCFLAGS", "--markdown-no-toc")
         .run();
 }
+
+#[test]
+fn rustdocflags_misspelled() {
+    let p = project().file("src/main.rs", "fn main() { }").build();
+
+    p.cargo("doc")
+        .env("RUSTDOC_FLAGS", "foo")
+        .with_stderr_contains("[WARNING] Cargo does not read `RUSTDOC_FLAGS` environment variable. Did you mean `RUSTDOCFLAGS`?")
+        .run();
+}
diff --git a/tests/testsuite/rustflags.rs b/tests/testsuite/rustflags.rs
index 84ee109748b..ba6171082d0 100644
--- a/tests/testsuite/rustflags.rs
+++ b/tests/testsuite/rustflags.rs
@@ -1325,3 +1325,37 @@ fn two_matching_in_config() {
     p1.cargo("run").run();
     p1.cargo("build").with_stderr("[FINISHED] [..]").run();
 }
+
+#[test]
+fn env_rustflags_misspelled() {
+    let p = project().file("src/main.rs", "fn main() { }").build();
+
+    for cmd in &["check", "build", "run", "test", "bench"] {
+        p.cargo(cmd)
+        .env("RUST_FLAGS", "foo")
+        .with_stderr_contains("[WARNING] Cargo does not read `RUST_FLAGS` environment variable. Did you mean `RUSTFLAGS`?")
+        .run();
+    }
+}
+
+#[test]
+fn env_rustflags_misspelled_build_script() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+            [package]
+            name = "foo"
+            version = "0.0.1"
+            build = "build.rs"
+        "#,
+        )
+        .file("src/lib.rs", "")
+        .file("build.rs", "fn main() { }")
+        .build();
+
+    p.cargo("build")
+        .env("RUST_FLAGS", "foo")
+        .with_stderr_contains("[WARNING] Cargo does not read `RUST_FLAGS` environment variable. Did you mean `RUSTFLAGS`?")
+        .run();
+}

From 3ca98adbbac5752cdef337f5ac803e7843ab601a Mon Sep 17 00:00:00 2001
From: Hidehito Yabuuchi <hdht.ybuc@gmail.com>
Date: Sun, 24 Feb 2019 14:27:10 +0900
Subject: [PATCH 3/3] cargo fmt tests/testsuite/rustflags.rs

---
 tests/testsuite/rustflags.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/testsuite/rustflags.rs b/tests/testsuite/rustflags.rs
index ba6171082d0..da5b5eb78c2 100644
--- a/tests/testsuite/rustflags.rs
+++ b/tests/testsuite/rustflags.rs
@@ -1332,9 +1332,9 @@ fn env_rustflags_misspelled() {
 
     for cmd in &["check", "build", "run", "test", "bench"] {
         p.cargo(cmd)
-        .env("RUST_FLAGS", "foo")
-        .with_stderr_contains("[WARNING] Cargo does not read `RUST_FLAGS` environment variable. Did you mean `RUSTFLAGS`?")
-        .run();
+            .env("RUST_FLAGS", "foo")
+            .with_stderr_contains("[WARNING] Cargo does not read `RUST_FLAGS` environment variable. Did you mean `RUSTFLAGS`?")
+            .run();
     }
 }