Set RUSTUP_TOOLCHAIN_SOURCE in rustup tests

Author: smoelius

tests/testsuite/rustup.rs

@@ -55,6 +55,13 @@ fn real_rustc_wrapper(bin_dir: &Path, message: &str) -> PathBuf {
     // The toolchain rustc needs to call the real rustc. In order to do that,
     // it needs to restore or clear the RUSTUP environment variables so that
     // if rustup is installed, it will call the correct rustc.
+    let rustup_toolchain_source_setup = match std::env::var_os("RUSTUP_TOOLCHAIN_SOURCE") {
+        Some(t) => format!(
+            ".env(\"RUSTUP_TOOLCHAIN_SOURCE\", \"{}\")",
+            t.into_string().unwrap()
+        ),
+        None => format!(".env_remove(\"RUSTUP_TOOLCHAIN_SOURCE\")"),
+    };
     let rustup_toolchain_setup = match std::env::var_os("RUSTUP_TOOLCHAIN") {
         Some(t) => format!(
             ".env(\"RUSTUP_TOOLCHAIN\", \"{}\")",
@@ -78,6 +85,7 @@ fn real_rustc_wrapper(bin_dir: &Path, message: &str) -> PathBuf {
                 eprintln!("{message}");
                 let r = std::process::Command::new(env!("CARGO_RUSTUP_TEST_real_rustc"))
                     .args(std::env::args_os().skip(1))
+                    {rustup_toolchain_source_setup}
                     {rustup_toolchain_setup}
                     {rustup_home_setup}
                     .status();
@@ -162,6 +170,7 @@ fn typical_rustup() {
     // `~/.cargo/bin/rustc to use our custom rustup proxies.
     let path = prepend_path(&cargo_bin);
     p.cargo("check")
+        .env("RUSTUP_TOOLCHAIN_SOURCE", "default")
         .env("RUSTUP_TOOLCHAIN", "test-toolchain")
         .env("RUSTUP_HOME", &rustup_home)
         .env("PATH", &path)
@@ -179,6 +188,7 @@ real rustc running
     p.build_dir().rm_rf();
 
     p.cargo("check")
+        .env("RUSTUP_TOOLCHAIN_SOURCE", "default")
         .env("RUSTUP_TOOLCHAIN", "test-toolchain")
         .env("RUSTUP_HOME", &rustup_home)
         .env("PATH", &path)
@@ -249,6 +259,7 @@ fn custom_calls_other_cargo() {
         // Set these to simulate what would happen when running under rustup.
         // We want to make sure that cargo-custom does not try to use the
         // rustup proxies.
+        .env("RUSTUP_TOOLCHAIN_SOURCE", "default")
         .env("RUSTUP_TOOLCHAIN", "test-toolchain")
         .env("RUSTUP_HOME", &rustup_home)
         .with_stderr_data(str![[r#"