Make rustdoc output deterministic for UI tests

diff --git a/src/test/rustdoc-ui/failed-doctest-output.rs b/src/test/rustdoc-ui/failed-doctest-output.rs
index fcbd7cabc69003f4d4dc7f0fc37e9f3e97e02e0c..90cdb5127bea25bb8a8bec9eacbf9b00e0a7552d 100644 (file)
--- a/src/test/rustdoc-ui/failed-doctest-output.rs
+++ b/src/test/rustdoc-ui/failed-doctest-output.rs
@@ -2,7 +2,7 @@
 // FIXME: if/when the output of the test harness can be tested on its own, this test should be
 // adapted to use that, and that normalize line can go away
 
-// compile-flags:--test
+// compile-flags:--test --test-args --test-threads=1
 // rustc-env:RUST_BACKTRACE=0
 // normalize-stdout-test: "src/test/rustdoc-ui" -> "$$DIR"
 // failure-status: 101