From 5e7b09ce9fbc95ec9fb9e277d262b9b5a5aa1917 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Sat, 18 Feb 2023 11:31:31 -0700
Subject: [PATCH] std.Build.RunStep: fix default caching logic

RunStep is supposed to auto-detect whether the intend is for
side-effects or for producing an output file. The auto-detection logic
was incorrect, and this commit fixes it.

I tested this manually locally. Automated testing will require a more
significant investment in the test harness, which I will work on in a
future enhancement.

closes #14666
---
 lib/std/Build/RunStep.zig | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/lib/std/Build/RunStep.zig b/lib/std/Build/RunStep.zig
index 5bc271409a..d3f48e4e87 100644
--- a/lib/std/Build/RunStep.zig
+++ b/lib/std/Build/RunStep.zig
@@ -188,6 +188,10 @@ fn stdIoActionToBehavior(action: StdIoAction) std.ChildProcess.StdIo {
 }
 
 fn needOutputCheck(self: RunStep) bool {
+    switch (self.condition) {
+        .always => return false,
+        .output_outdated => {},
+    }
     if (self.extra_file_dependencies.len > 0) return true;
 
     for (self.argv.items) |arg| switch (arg) {
@@ -195,10 +199,7 @@ fn needOutputCheck(self: RunStep) bool {
         else => continue,
     };
 
-    return switch (self.condition) {
-        .always => false,
-        .output_outdated => true,
-    };
+    return false;
 }
 
 fn make(step: *Step) !void {