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1 files changed, 6 insertions, 0 deletions

diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index 3847a2a1e46..f1bb318651a 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1186,6 +1186,12 @@ impl Step for Compiletest {
             })
             .filter(|p| p.starts_with(suite_path) && (p.is_dir() || p.is_file()))
             .filter_map(|p| {
+                // Since test suite paths are themselves directories, if we don't
+                // specify a directory or file, we'll get an empty string here
+                // (the result of the test suite directory without its suite prefix).
+                // Therefore, we need to filter these out, as only the first --test-args
+                // flag is respected, so providing an empty --test-args conflicts with
+                // any following it.
                 match p.strip_prefix(suite_path).ok().and_then(|p| p.to_str()) {
                     Some(s) if s != "" => Some(s),
                     _ => None,