wip: rust code won't compile

* use local repo to debug
  - rust_rules needs generator_urls provided. use Github release page
  - needs to add edition attr. to rust_binary/_image method by some
    reasons.
* toolchain not found for cpp (or rust).
* can build and run rust_binary solely, but with rust_image it fails with
  toolchain not found error.
* image_transition target seems missing os/cpu target.
* disable image_transition avoid this issue. But instead causing
  linux exec format error. Need to choose amd64 platform target?
  - rust_binary can run without selecting amd64 platform, but
    rust_image.
* it seems rust rules do not provide platform definition for our case.
  manually adding a custom platform for linux/x86_64 target.
  setting this to --target_platform resolves execution platform for
  rust. However, we still have resolution error with cpp toolchain,
  because it seems there are no linux/x86_64 toolchain?
* execution (also host?) platform is aarch64/osx by local_config.
* rust's toolchain doesn't have exec_compatible_with aarch64/osx
  and target_compatible_with amd64/linux.
* Only reasonable rust toolchain which can run on x86 docker is
  to have x86 target for both exe_/target_compatible_with.
  But now we still miss cpp_toolchain for that combination.
* cpp toolchains are auto-generated by cc_configure methods which
  use local_config information coupled with m1 mac. So it does not
  contain x86/linux pattens.
* another solution is to replace docker base image to arm64 image.
  can override image base by 'base' option in rust_image.
* even using aarch64 docker image and arm64 binary, it gives Exec format
  error. Why?
  - Turned out the binary has Mach-O format, which is only for M1?, but
    not ELF format.
* cc_toolchain does not have x86 or aarch64, linux target compatible
  toolchain, but only x86 or aarch64 and osx.
  - cc_toolchain does not have non-osx exec_compatible toolchain,
    because bazel auto-detect osx local env to make osx only toolchains.
  - check cc_configure.bzl.
* rust only have x86,linux -> x86,linux, or aarch64,linux ->
  aarch64,linux exec_/target_compatible combination.
* normal build outputs Mach-O format, not able to run on docker images
  which are mostly based on linux and supports ELF format.
* image_transition generates new settings with proper cpu/os parameters
  but actually set nothing. Not sure why
* Only way to solve this issue is to write a custom toolchain for cpp or
  generate it from the official implementation for osx/arm64 ->
  linux/amd64 or arm64 cross compilation.
* needs to write osx/aarch64 -> linux/amd64 cross compile toolchain for
  both rust and cpp.
* ref. bazelbuild/rules_rust#276

go_rust/bazel_docker_test/.bazelrc

@@ -0,0 +1,2 @@
+build:macos --@io_bazel_rules_docker//transitions:enable=false
+build:macos --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64

go_rust/bazel_docker_test/.gitignore

@@ -0,0 +1 @@
+bazel-*

go_rust/bazel_docker_test/Cargo.Bazel.lock

@@ -0,0 +1,67 @@
+{
+  "checksum": "1880b9ea81e4dbd47ad152a782f5435714718268b6b878574eb80910a38d5bdc",
+  "crates": {
+    "direct-cargo-bazel-deps 0.0.1": {
+      "name": "direct-cargo-bazel-deps",
+      "version": "0.0.1",
+      "repository": null,
+      "targets": [
+        {
+          "Library": {
+            "crate_name": "direct_cargo_bazel_deps",
+            "crate_root": ".direct_cargo_bazel_deps.rs",
+            "srcs": {
+              "include": [
+                "**/*.rs"
+              ],
+              "exclude": []
+            }
+          }
+        }
+      ],
+      "library_target_name": "direct_cargo_bazel_deps",
+      "common_attrs": {
+        "compile_data_glob": [
+          "**"
+        ],
+        "edition": "2018",
+        "version": "0.0.1"
+      },
+      "license": null
+    },
+    "hello_rust 0.1.0": {
+      "name": "hello_rust",
+      "version": "0.1.0",
+      "repository": null,
+      "targets": [
+        {
+          "Binary": {
+            "crate_name": "hello_rust",
+            "crate_root": "src/main.rs",
+            "srcs": {
+              "include": [
+                "**/*.rs"
+              ],
+              "exclude": []
+            }
+          }
+        }
+      ],
+      "library_target_name": null,
+      "common_attrs": {
+        "compile_data_glob": [
+          "**"
+        ],
+        "edition": "2021",
+        "version": "0.1.0"
+      },
+      "license": null
+    }
+  },
+  "binary_crates": [],
+  "workspace_members": {
+    "direct-cargo-bazel-deps 0.0.1": "",
+    "hello_rust 0.1.0": "hello_rust"
+  },
+  "conditions": {}
+}

go_rust/bazel_docker_test/Cargo.toml

@@ -0,0 +1,5 @@
+[workspace]
+
+members = [
+  "hello_rust",
+]

go_rust/bazel_docker_test/WORKSPACE

@@ -0,0 +1,100 @@
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+# go
+http_archive(
+    name = "io_bazel_rules_go",
+    sha256 = "16e9fca53ed6bd4ff4ad76facc9b7b651a89db1689a2877d6fd7b82aa824e366",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.34.0/rules_go-v0.34.0.zip",
+        "https://github.com/bazelbuild/rules_go/releases/download/v0.34.0/rules_go-v0.34.0.zip",
+    ],
+)
+
+load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
+
+go_rules_dependencies()
+
+go_register_toolchains(version = "1.18.3")
+
+http_archive(
+    name = "bazel_gazelle",
+    sha256 = "5982e5463f171da99e3bdaeff8c0f48283a7a5f396ec5282910b9e8a49c0dd7e",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-gazelle/releases/download/v0.25.0/bazel-gazelle-v0.25.0.tar.gz",
+        "https://github.com/bazelbuild/bazel-gazelle/releases/download/v0.25.0/bazel-gazelle-v0.25.0.tar.gz",
+    ],
+)
+
+load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
+
+gazelle_dependencies()
+
+# rust
+http_archive(
+    name = "rules_rust",
+    sha256 = "39655ab175e3c6b979f362f55f58085528f1647957b0e9b3a07f81d8a9c3ea0a",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_rust/releases/download/0.2.0/rules_rust-v0.2.0.tar.gz",
+        "https://github.com/bazelbuild/rules_rust/releases/download/0.2.0/rules_rust-v0.2.0.tar.gz",
+    ],
+)
+
+load("@rules_rust//rust:repositories.bzl", "rules_rust_dependencies", "rust_register_toolchains")
+
+rules_rust_dependencies()
+
+rust_register_toolchains()
+
+load("@rules_rust//crate_universe:repositories.bzl", "crate_universe_dependencies")
+
+crate_universe_dependencies()
+
+load("@rules_rust//crate_universe:defs.bzl", "crates_repository")
+
+crates_repository(
+    name = "crate_index",
+    lockfile = "//:Cargo.Bazel.lock",
+    manifests = [
+        "//:Cargo.toml",
+        "//hello_rust:Cargo.toml",
+    ],
+)
+
+load("@crate_index//:defs.bzl", "crate_repositories")
+
+crate_repositories()
+
+# rules_docker
+http_archive(
+    name = "io_bazel_rules_docker",
+    sha256 = "b1e80761a8a8243d03ebca8845e9cc1ba6c82ce7c5179ce2b295cd36f7e394bf",
+    urls = ["https://github.com/bazelbuild/rules_docker/releases/download/v0.25.0/rules_docker-v0.25.0.tar.gz"],
+)
+
+load(
+    "@io_bazel_rules_docker//repositories:repositories.bzl",
+    container_repositories = "repositories",
+)
+
+container_repositories()
+
+# NOTE: it installs go-v0.24.2.tar.gz which contains go v1.15.2.
+load("@io_bazel_rules_docker//repositories:deps.bzl", container_deps = "deps")
+
+container_deps()
+
+# rules_docker go
+load(
+    "@io_bazel_rules_docker//go:image.bzl",
+    _go_image_repos = "repositories",
+)
+
+_go_image_repos()
+
+# rules_docker rust
+load(
+    "@io_bazel_rules_docker//rust:image.bzl",
+    _rust_image_repos = "repositories",
+)
+
+_rust_image_repos()

go_rust/bazel_docker_test/hello_go/BUILD

@@ -0,0 +1,6 @@
+load("@io_bazel_rules_docker//go:image.bzl", "go_image")
+
+go_image(
+    name = "hello_go",
+    srcs = ["src/main.go"],
+)

go_rust/bazel_docker_test/hello_go/src/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	fmt.Println("Hello, World in go")
+}

go_rust/bazel_docker_test/hello_rust/BUILD

@@ -0,0 +1,15 @@
+load("@crate_index//:defs.bzl", "aliases", "all_crate_deps")
+load("@io_bazel_rules_docker//rust:image.bzl", "rust_image")
+
+rust_image(
+    name = "hello_rust",
+    srcs = glob(["src/*.rs"]),
+    aliases = aliases(),
+    proc_macro_deps = all_crate_deps(
+        proc_macro = True,
+    ),
+    visibility = ["//visibility:public"],
+    deps = all_crate_deps(
+        normal = True,
+    ),
+)

go_rust/bazel_docker_test/hello_rust/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "hello_rust"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+#[dependencies]
+#thiserror = "1.0"

go_rust/bazel_docker_test/hello_rust/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}

rust/.bazelrc

@@ -0,0 +1,2 @@
+build:macos --@io_bazel_rules_docker//transitions:enable=false
+build:macos --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64

rust/.gitignore

@@ -0,0 +1,2 @@
+bazel-*
+target

rust/Cargo.Bazel.lock

@@ -0,0 +1,67 @@
+{
+  "checksum": "e6768397ef18bbbd463dab1c6e13c5a9d8783642c08dcc6f875f59eb0c31a3d6",
+  "crates": {
+    "direct-cargo-bazel-deps 0.0.1": {
+      "name": "direct-cargo-bazel-deps",
+      "version": "0.0.1",
+      "repository": null,
+      "targets": [
+        {
+          "Library": {
+            "crate_name": "direct_cargo_bazel_deps",
+            "crate_root": ".direct_cargo_bazel_deps.rs",
+            "srcs": {
+              "include": [
+                "**/*.rs"
+              ],
+              "exclude": []
+            }
+          }
+        }
+      ],
+      "library_target_name": "direct_cargo_bazel_deps",
+      "common_attrs": {
+        "compile_data_glob": [
+          "**"
+        ],
+        "edition": "2018",
+        "version": "0.0.1"
+      },
+      "license": null
+    },
+    "hello 0.1.0": {
+      "name": "hello",
+      "version": "0.1.0",
+      "repository": null,
+      "targets": [
+        {
+          "Binary": {
+            "crate_name": "hello",
+            "crate_root": "src/main.rs",
+            "srcs": {
+              "include": [
+                "**/*.rs"
+              ],
+              "exclude": []
+            }
+          }
+        }
+      ],
+      "library_target_name": null,
+      "common_attrs": {
+        "compile_data_glob": [
+          "**"
+        ],
+        "edition": "2021",
+        "version": "0.1.0"
+      },
+      "license": null
+    }
+  },
+  "binary_crates": [],
+  "workspace_members": {
+    "direct-cargo-bazel-deps 0.0.1": "",
+    "hello 0.1.0": "hello"
+  },
+  "conditions": {}
+}

rust/Cargo.toml

@@ -0,0 +1,5 @@
+[workspace]
+
+members = [
+  "hello",
+]