From 0db7eadccdb926e2c2aa952e66a2d46d29c3bbe9 Mon Sep 17 00:00:00 2001
From: Ryan Liptak <squeek502@hotmail.com>
Date: Fri, 11 Sep 2026 23:11:08 -0700
Subject: [PATCH] Compilation: close the linker output file before writing
 whole cache manifest

The issue that this fixes was previously fixed in 5e0e1841c0, but regressed in 77a4c4bbcf.

This is something of a combination of both changes:
- `comp.bin_file` remains non-null so the defer can run to update the progress node
- Closing the file and releasing the lock has been re-introduced, which is the important bit of the `destroy()` call that was removed in 77a4c4bbcf

Closes https://codeberg.org/ziglang/zig/issues/36651
---
 src/Compilation.zig | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/Compilation.zig b/src/Compilation.zig
index 711b434c57d85cd9f6ae6df784f4b73a529b4b1e..d1a95dd5f2ac14df15161547b5d3f1351bd10a8e 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -3151,6 +3151,17 @@ pub fn update(comp: *Compilation, main_progress_node: std.Progress.Node) UpdateE
             // cache manifest must not be written.
             if (anyErrors(comp)) return;
 
+            // Release the lock and close the file before writing the manifest.
+            // This avoids the potential of another process getting a cache hit and
+            // trying to spawn a process with it while there's still an open fd to it.
+            if (comp.bin_file) |lf| {
+                lf.releaseLock();
+                if (lf.file) |f| {
+                    f.close(io);
+                    lf.file = null;
+                }
+            }
+
             // Failure here only means an unnecessary cache miss.
             man.writeManifest() catch |err| log.warn("failed to write cache manifest: {t}", .{err});
 
-- 
2.54.0