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.

2 files changed, 15 insertions, 3 deletions

diff --git a/src/test/ui/test-panic-abort.rs b/src/test/ui/test-panic-abort.rs
index b0679ea1d3d..b7bf5a150ea 100644
--- a/src/test/ui/test-panic-abort.rs
+++ b/src/test/ui/test-panic-abort.rs
@@ -11,6 +11,7 @@
 #![cfg(test)]
 
 use std::io::Write;
+use std::env;
 
 #[test]
 fn it_works() {
@@ -35,3 +36,13 @@ fn it_fails() {
 fn it_exits() {
     std::process::exit(123);
 }
+
+#[test]
+fn no_residual_environment() {
+    for (key, _) in env::vars() {
+        // Look for keys like __RUST_TEST_INVOKE.
+        if key.contains("TEST_INVOKE") {
+            panic!("shouldn't have '{}' in environment", key);
+        }
+    }
+}
diff --git a/src/test/ui/test-panic-abort.run.stdout b/src/test/ui/test-panic-abort.run.stdout
index 46adcfbc2eb..2f4bc32ed6a 100644
--- a/src/test/ui/test-panic-abort.run.stdout
+++ b/src/test/ui/test-panic-abort.run.stdout
@@ -1,9 +1,10 @@
 
-running 4 tests
+running 5 tests
 test it_exits ... FAILED
 test it_fails ... FAILED
 test it_panics ... ok
 test it_works ... ok
+test no_residual_environment ... ok
 
 failures:
 
@@ -17,7 +18,7 @@ testing123
 testing321
 thread 'main' panicked at 'assertion failed: `(left == right)`
   left: `2`,
- right: `5`', $DIR/test-panic-abort.rs:31:5
+ right: `5`', $DIR/test-panic-abort.rs:32:5
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 
 
@@ -25,5 +26,5 @@ failures:
     it_exits
     it_fails
 
-test result: FAILED. 2 passed; 2 failed; 0 ignored; 0 measured; 0 filtered out
+test result: FAILED. 3 passed; 2 failed; 0 ignored; 0 measured; 0 filtered out