Add news about prebuilt protoc option with Bazel 9.

PiperOrigin-RevId: 857301460

Author: protobuf-github-bot

content/news/2026-01-16.md

@@ -0,0 +1,34 @@
++++
+title = "Changes Announced on January 16, 2026"
+linkTitle = "January 16, 2026"
+toc_hide = "true"
+description = "Changes announced for Protocol Buffers on January 16, 2026."
+type = "docs"
++++
+
+## Prebuilt proto compiler (protoc) for Bazel
+
+In an effort to speed up builds, Bazel 9 provides an option to skip re-compiling
+Protobuf tools and runtimes and use a pre-built protoc binary. Using a pre-built
+protoc also avoids build failures from incompatible or non-hermetic C++
+compilation toolchain installed on your machine.
+
+To use the prebuilt protoc, you must be using Bazel 9 or later, which itself
+requires protobuf version 33.4 or later. Set the
+`--@protobuf//bazel/toolchains:prefer_prebuilt_protoc` flag to use the prebuilt
+protoc. The default will be changed to use the prebuilt protoc with the breaking
+v34 release.
+
+### Reasons not to use the prebuilt compiler
+
+There are some use cases in which using the prebuilt protoc is not recommended:
+
+*   Your corporate security policy requires all dependencies be built from
+    source.
+*   You need to build for the exec platform with a specific compiler or specific
+    compiler flags.
+*   You are making changes to protoc, itself, and want to ensure that those
+    changes are tested.
+
+For more information on other changes in Bazel 9 that affect Protocol Buffers,
+see https://bazel.build/about/roadmap.

content/news/_index.md

@@ -20,6 +20,8 @@ New news topics will also be published to the
 The following news topics provide information in the reverse order in which it
 was released.
 
+*   [January 16, 2026](/news/2026-01-16) - Prebuilt proto
+    compiler (protoc) for Bazel
 *   [September 19, 2025](/news/2025-09-19) - Breaking
     changes in the upcoming 34.x release
 *   [July 16, 2025](/news/2025-07-16) - Resuming support