update lockStderrWriter sites

use the application's Io implementation where possible. This correctly
makes writing to stderr cancelable, fallible, and participate in the
application's event loop. It also removes one more hard-coded
dependency on a secondary Io implementation.

1 files changed, 12 insertions, 4 deletions

diff --git a/lib/std/testing.zig b/lib/std/testing.zig
index 092b65d71a..64ea3d1a4d 100644
--- a/lib/std/testing.zig
+++ b/lib/std/testing.zig
@@ -368,13 +368,21 @@ pub fn expectEqualSlices(comptime T: type, expected: []const T, actual: []const
         break :diff_index if (expected.len == actual.len) return else shortest;
     };
     if (!backend_can_print) return error.TestExpectedEqual;
-    const stderr = std.debug.lockStderrWriter(&.{});
-    defer std.debug.unlockStderrWriter();
-    failEqualSlices(T, expected, actual, diff_index, &stderr.interface, stderr.mode) catch {};
+    if (io.lockStderrWriter(&.{})) |stderr| {
+        defer io.unlockStderrWriter();
+        failEqualSlices(T, expected, actual, diff_index, &stderr.interface, stderr.mode) catch {};
+    } else |_| {}
     return error.TestExpectedEqual;
 }
 
-fn failEqualSlices(comptime T: type, expected: []const T, actual: []const T, diff_index: usize, w: *Io.Writer, fwm: Io.File.Writer.Mode) !void {
+fn failEqualSlices(
+    comptime T: type,
+    expected: []const T,
+    actual: []const T,
+    diff_index: usize,
+    w: *Io.Writer,
+    fwm: Io.File.Writer.Mode,
+) !void {
     try w.print("slices differ. first difference occurs at index {d} (0x{X})\n", .{ diff_index, diff_index });
 
     // TODO: Should this be configurable by the caller?