run_dep_mode: treat program.args and program.env consistently

Author: RalfJung

tests/ui.rs

@@ -59,6 +59,13 @@ fn test_config(target: &str, path: &str, mode: Mode, with_dependencies: bool) ->
     let mut program = CommandBuilder::rustc();
     program.program = miri_path();
 
+    // Add a test env var to do environment communication tests.
+    program.envs.push(("MIRI_ENV_VAR_TEST".into(), Some("0".into())));
+    // Let the tests know where to store temp files (they might run for a different target, which can make this hard to find).
+    program.envs.push(("MIRI_TEMP".into(), Some(tmpdir.to_owned().into())));
+    // If a test ICEs, we want to see a backtrace.
+    program.envs.push(("RUST_BACKTRACE".into(), Some("1".into())));
+
     // Add some flags we always want.
     program.args.push(
         format!(
@@ -128,15 +135,6 @@ fn run_tests(
 ) -> Result<()> {
     let mut config = test_config(target, path, mode, with_dependencies);
 
-    // Add a test env var to do environment communication tests.
-    config.program.envs.push(("MIRI_ENV_VAR_TEST".into(), Some("0".into())));
-
-    // Let the tests know where to store temp files (they might run for a different target, which can make this hard to find).
-    config.program.envs.push(("MIRI_TEMP".into(), Some(tmpdir.to_owned().into())));
-
-    // If a test ICEs, we want to see a backtrace.
-    config.program.envs.push(("RUST_BACKTRACE".into(), Some("1".into())));
-
     // Handle command-line arguments.
     let args = ui_test::Args::test()?;
     let default_bless = env::var_os("RUSTC_BLESS").is_some_and(|v| v != "0");
@@ -306,6 +304,7 @@ fn run_dep_mode(target: String, mut args: impl Iterator<Item = OsString>) -> Res
         /* with dependencies */ true,
     );
     config.program.args.clear(); // We want to give the user full control over flags
+    config.program.env.clear(); // and the env
     let dep_args = config.build_dependencies()?;
 
     let mut cmd = config.program.build(&config.out_dir);