README.md - third_party/github/aspect-build/toolchains_protoc - Git at Google

 # Bazel toolchain for pre-built protoc

 Using Protocol Buffers with Bazel has always been painful.

 - Nearly every Bazel user has waited for `protoc` to compile from sources many, MANY times.
 - The versioning of the protobuf module on Bazel Central Registry has fallen behind and contains many patches.
 - Relying on the protobuf runtime for each language from the `@com_google_protobuf` repo forces you to use
   the same version of the runtime for all languages in a monorepo, and matching protoc.

 The key observations:

 - `protoc` has always been distributed as pre-built binaries on https://github.com/protocolbuffers/protobuf/releases
 - the protobuf runtimes for each language are distributed to the appropriate package manager

 Bazel 7 introduced `--incompatible_enable_proto_toolchain_resolution` to allow us fetch `protoc` rather than re-build it!
 That flag ALSO decouples how each language rule locates the runtime.

 This repo simply contains a toolchain that resolves those pre-built binaries.

 See `examples` for several language rules like `py_proto_library` and `java_proto_library`.
 There is NO dependency on `@com_google_protobuf` anywhere.

 ## Design

 ### Questioning why Bazel is different

 Protobuf works fine under many build tools, using the releases and runtime libraries shipped by the protobuf team.
 Why is Bazel different?

 Our answer is: it should not be. The protobuf team shouldn’t have to own Bazel rules or understand bzlmod.
 As with many other tools such as Swagger and GraphQL, the Bazel community is self-sufficient to create thin layers to establish a toolchain and execute actions that perform codegen steps.

 This toolchain shows that there's no need to treat Bazel as a “special” build system vs. all the others that protobuf users rely on.
 https://protobuf.dev/reference/ is sufficient documentation for everyone.

 ### Why a separate Bazel module?

 This belongs in rules_proto, see

 - https://github.com/bazelbuild/rules_proto/pull/205
 - https://github.com/bazelbuild/rules_proto/pull/206

 Getting reviews from Googlers is hard so let's not wait for them.

 ## Installation

 Make sure your `.bazelrc` contains

 ```
 # Introduced in Bazel 7.
 common --incompatible_enable_proto_toolchain_resolution
 ```

 Follow instructions from the release you wish to use:
 <https://github.com/alexeagle/toolchains_protoc/releases>
	# Bazel toolchain for pre-built protoc

	Using Protocol Buffers with Bazel has always been painful.

	- Nearly every Bazel user has waited for `protoc` to compile from sources many, MANY times.
	- The versioning of the protobuf module on Bazel Central Registry has fallen behind and contains many patches.
	- Relying on the protobuf runtime for each language from the `@com_google_protobuf` repo forces you to use
	the same version of the runtime for all languages in a monorepo, and matching protoc.

	The key observations:

	- `protoc` has always been distributed as pre-built binaries on https://github.com/protocolbuffers/protobuf/releases
	- the protobuf runtimes for each language are distributed to the appropriate package manager

	Bazel 7 introduced `--incompatible_enable_proto_toolchain_resolution` to allow us fetch `protoc` rather than re-build it!
	That flag ALSO decouples how each language rule locates the runtime.

	This repo simply contains a toolchain that resolves those pre-built binaries.

	See `examples` for several language rules like `py_proto_library` and `java_proto_library`.
	There is NO dependency on `@com_google_protobuf` anywhere.

	## Design

	### Questioning why Bazel is different

	Protobuf works fine under many build tools, using the releases and runtime libraries shipped by the protobuf team.
	Why is Bazel different?

	Our answer is: it should not be. The protobuf team shouldn’t have to own Bazel rules or understand bzlmod.
	As with many other tools such as Swagger and GraphQL, the Bazel community is self-sufficient to create thin layers to establish a toolchain and execute actions that perform codegen steps.

	This toolchain shows that there's no need to treat Bazel as a “special” build system vs. all the others that protobuf users rely on.
	https://protobuf.dev/reference/ is sufficient documentation for everyone.

	### Why a separate Bazel module?

	This belongs in rules_proto, see

	- https://github.com/bazelbuild/rules_proto/pull/205
	- https://github.com/bazelbuild/rules_proto/pull/206

	Getting reviews from Googlers is hard so let's not wait for them.

	## Installation

	Make sure your `.bazelrc` contains

	```
	# Introduced in Bazel 7.
	common --incompatible_enable_proto_toolchain_resolution
	```

	Follow instructions from the release you wish to use:
	<https://github.com/alexeagle/toolchains_protoc/releases>