syscall: document relationship among Errno, errors.Is and os.Err*
- Add doc to syscall.Errno (and syscall.ErrorString for plan9).
- Mention under `syscall` in release notes.
Fixes #33436.
Change-Id: I032ffebaa76ed67eb9d748e7645ca73f26144ea0
Reviewed-on: https://go-review.googlesource.com/c/go/+/191337
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/doc/go1.13.html b/doc/go1.13.html
index 6cee0b2..5760669 100644
--- a/doc/go1.13.html
+++ b/doc/go1.13.html
@@ -961,6 +961,13 @@
<a href="/pkg/syscall/?GOOS=windows#Chmod"><code>Chmod</code></a> mode on Windows.
</p>
+ <p><!-- CL 191337 -->
+ Values of type <code>Errno</code> can be tested against error values in
+ the <code>os</code> package,
+ like <a href="/pkg/os/#ErrExist"><code>ErrExist</code></a>, using
+ <a href="/pkg/errors/#Is"><code>errors.Is</code></a>.
+ </p>
+
</dl><!-- syscall -->
<dl id="syscall/js"><dt><a href="/pkg/syscall/js/">syscall/js</a></dt>
