Don't propagate __RUST_TEST_INVOKE to subprocess

When -Z panic_abort_tests is enabled, we use an environment variable to
tell the subprocess which test to invoke. If that subprocess then
invokes another Rust test binary, chaos ensues.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/libtest/lib.rs b/src/libtest/lib.rs
index 45669d120c7..7782f62d6ed 100644
--- a/src/libtest/lib.rs
+++ b/src/libtest/lib.rs
@@ -153,12 +153,13 @@ pub fn test_main_static_abort(tests: &[&TestDescAndFn]) {
     // If we're being run in SpawnedSecondary mode, run the test here. run_test
     // will then exit the process.
     if let Ok(name) = env::var(SECONDARY_TEST_INVOKER_VAR) {
+        env::remove_var(SECONDARY_TEST_INVOKER_VAR);
         let test = tests
             .iter()
             .filter(|test| test.desc.name.as_slice() == name)
             .map(make_owned_test)
             .next()
-            .expect("couldn't find a test with the provided name");
+            .expect(&format!("couldn't find a test with the provided name '{}'", name));
         let TestDescAndFn { desc, testfn } = test;
         let testfn = match testfn {
             StaticTestFn(f) => f,