From c8ecfad41a322260fae38a4115a94345ed9f94b7 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Sun, 4 Jan 2026 17:46:44 -0800
Subject: [PATCH] build runner: clean up tmp dirs

---
 lib/compiler/build_runner.zig | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/lib/compiler/build_runner.zig b/lib/compiler/build_runner.zig
index 395ae76426e5e5068b58242d8e07bfeea516c9f4..e479ca725a9c0b5041832e069120c9ca0b98c1d6 100644
--- a/lib/compiler/build_runner.zig
+++ b/lib/compiler/build_runner.zig
@@ -784,6 +784,9 @@ fn runStepNames(
     var pending_count: usize = 0;
     var total_compile_errors: usize = 0;
 
+    var cleanup_task = io.async(cleanTmpFiles, .{ io, step_stack.keys() });
+    defer cleanup_task.await(io);
+
     for (step_stack.keys()) |s| {
         test_pass_count += s.test_results.passCount();
         test_skip_count += s.test_results.skip_count;
@@ -1849,3 +1852,14 @@ fn initStdoutWriter(io: Io) *Writer {
     stdout_writer_allocation = Io.File.stdout().writerStreaming(io, &stdio_buffer_allocation);
     return &stdout_writer_allocation.interface;
 }
+
+fn cleanTmpFiles(io: Io, steps: []const *Step) void {
+    for (steps) |step| {
+        const wf = step.cast(std.Build.Step.WriteFile) orelse continue;
+        if (wf.mode != .tmp) continue;
+        const path = wf.generated_directory.path orelse continue;
+        Io.Dir.cwd().deleteTree(io, path) catch |err| {
+            std.log.warn("failed to delete {s}: {t}", .{ path, err });
+        };
+    }
+}
-- 
2.54.0