From ff8a889b3d3d86a5872def68c0181a2f10ca3b4f Mon Sep 17 00:00:00 2001
From: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>
Date: Wed, 31 Jan 2024 13:26:45 -0800
Subject: [PATCH] Update PipeReader.zig

---
 src/io/PipeReader.zig | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/io/PipeReader.zig b/src/io/PipeReader.zig
index 572c68d36e..0749723676 100644
--- a/src/io/PipeReader.zig
+++ b/src/io/PipeReader.zig
@@ -27,8 +27,10 @@ pub fn PosixPipeReader(
             const buffer = @call(.always_inline, vtable.getBuffer, .{this});
             const fd = @call(.always_inline, vtable.getFd, .{this});
             if (comptime bun.Environment.isLinux) {
-                readFromBlockingPipeWithoutBlockingLinux(this, buffer, fd, 0);
-                return;
+                if (bun.C.linux.RWFFlagSupport.isMaybeSupported()) {
+                    readFromBlockingPipeWithoutBlockingLinux(this, buffer, fd, 0);
+                    return;
+                }
             }
 
             switch (bun.isReadable(fd)) {
@@ -61,11 +63,6 @@ pub fn PosixPipeReader(
             }
         }
 
-        const readFromBlockingPipeWithoutBlocking = if (bun.Environment.isLinux)
-            readFromBlockingPipeWithoutBlockingLinux
-        else
-            readFromBlockingPipeWithoutBlockingPOSIX;
-
         // On Linux, we use preadv2 to read without blocking.
         fn readFromBlockingPipeWithoutBlockingLinux(parent: *This, resizable_buffer: *std.ArrayList(u8), fd: bun.FileDescriptor, size_hint: isize) void {
             if (size_hint > stack_buffer_len) {
@@ -120,6 +117,17 @@ pub fn PosixPipeReader(
             }
         }
 
+        fn readFromBlockingPipeWithoutBlocking(parent: *This, resizable_buffer: *std.ArrayList(u8), fd: bun.FileDescriptor, size_hint: isize) void {
+            if (comptime bun.Environment.isLinux) {
+                if (bun.C.linux.RWFFlagSupport.isMaybeSupported()) {
+                    readFromBlockingPipeWithoutBlockingLinux(parent, resizable_buffer, fd, size_hint);
+                    return;
+                }
+            }
+
+            readFromBlockingPipeWithoutBlockingPOSIX(parent, resizable_buffer, fd, size_hint);
+        }
+
         fn readFromBlockingPipeWithoutBlockingPOSIX(parent: *This, resizable_buffer: *std.ArrayList(u8), fd: bun.FileDescriptor, size_hint: isize) void {
             if (size_hint > stack_buffer_len) {
                 resizable_buffer.ensureUnusedCapacity(@intCast(size_hint)) catch bun.outOfMemory();