fix(windows): normalize Windows platform names in all toolchain files #193
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Windows builds have been failing on Windows Server 2025 with error:
"Unsupported platform windows server 2025_amd64"
The issue was that platform detection did not normalize Windows OS names.
GitHub Actions now uses "Windows Server 2025" which becomes
"windows server 2025_amd64" after lowercasing, but the checksum registry
expects "windows_amd64".
Changes:
- Fixed platform detection in 7 toolchain files to normalize Windows names:
* wasm_toolchain.bzl
* wasmtime_toolchain.bzl
* jco_toolchain.bzl
* wasi_sdk_toolchain.bzl
* cpp_component_toolchain.bzl
* symmetric_wit_bindgen_toolchain.bzl
* monitoring.bzl
- Note: tinygo_toolchain.bzl, wizer_toolchain.bzl, and wkg_toolchain.bzl
already had correct implementations
- Enabled Windows tests in PR CI (was only running on main branch)
* Reduced test matrix to latest Bazel versions only on PRs
* This ensures Windows issues are caught early
The fix uses pattern matching ("windows" in os_name) instead of exact
string comparison, so it will work with any Windows variant:
- Windows 10, Windows 11
- Windows Server 2019, 2022, 2025
- Future Windows versions
Windows releases of wasm-tools use .zip format, not .tar.gz format. This was causing 404 errors when trying to download wasm-tools on Windows. Changes: - Update wasm-tools.json: Change url_suffix from .tar.gz to .zip for all Windows entries - Update checksums to match actual Windows .zip files: - v1.235.0: ecf9f2064c2096df134c39c2c97af2c025e974cc32e3c76eb2609156c1690a74 (unchanged) - v1.239.0: 039b1eaa170563f762355a23c5ee709790199433e35e5364008521523e9e3398 (updated) - v1.240.0: 81f012832e80fe09d384d86bb961d4779f6372a35fa965cc64efe318001ab27e (updated) - Update _download_wasm_tools() to handle both .zip and .tar.gz archives Fixes: bytecodealliance/wasm-tools Windows download errors in BCR CI
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Windows wkg checksum was wrong - using old wasm-tools checksum by mistake. Correct checksum: 930adea31da8d2a572860304c00903f7683966e722591819e99e26787e58416b Wrong checksum: 0019dfc4b32d63c1392aa264aed2253c1e0c2fb09216f8e2cc269bbfb8bb49b5 Fixed in all 3 locations: - checksums/tools/wkg.json - checksums/registry.bzl - toolchains/wkg_toolchain.bzl
Windows wac checksum was wrong for both v0.7.0 and v0.8.0. Also added missing v0.8.0 entry to wac.json (was only in registry.bzl). Correct checksum: 7ee34ea41cd567b2578929acce3c609e28818d03f0414914a3939f066737d872 Wrong checksum: d8c65e5471fc242d8c4993e2125912e10e9373f1e38249157491b3c851bd1336
v0.46.0 was using v0.43.0's Windows checksum (copypaste error). Correct v0.46.0 checksum: 95c6380ec7c1e385be8427a2da1206d90163fd66b6cbb573a516390988ccbad2 Wrong checksum (from v0.43.0): e133d9f18bc0d8a3d848df78960f9974a4333bee7ed3f99b4c9e900e9e279029
…proach - Document dependency management patterns in CLAUDE.md with clear decision matrix - Simplify toolchain strategies to download-only (remove build/source/hybrid options) - Migrate wasmsign2-cli to JSON registry for consistent security auditing - Clean up JSON registry files to keep only latest + previous stable versions * wasm-tools: 4 versions → 2 (1.240.0, 1.239.0) * file-ops-component: 3 versions → 2 (rc.3, rc.2) * nodejs: 3 versions → 2 (20.18.0, 18.20.8) * wasi-sdk: 3 versions → 2 (27, 26) * wasmtime: 3 versions → 2 (37.0.2, 35.0.0) - Update MODULE.bazel to use download strategy for wasm_toolchain This establishes clear patterns: - Multi-platform GitHub binaries → JSON Registry + secure_download - Bazel Central Registry deps → bazel_dep - Source builds → git_repository (when needed) - Universal WASM binaries → JSON Registry - NPM packages → hermetic npm Benefits: faster builds (prebuilt binaries), easier security audits (central checksums), simpler maintenance (one strategy per tool), clear documentation.
- Remove bazel/build/hybrid strategy support from wasm_toolchain.bzl - Simplify to download-only strategy (matching extensions.bzl cleanup) - Delete orphaned BUILD.wasm_tools_bazel and BUILD.wizer_bazel files - Add these files to .gitignore to prevent regeneration - Remove _setup_bazel_native_tools function (dead code) - Update all strategy references and error messages This completes the dependency management consolidation by removing unreachable code paths and simplifying the toolchain to use only prebuilt binary downloads from GitHub releases.
The stripPrefix was not removing .zip extension for Windows archives,
causing extraction errors on Windows CI:
Error: Prefix "wit-bindgen-0.46.0-x86_64-windows.zip" not found
Should be: "wit-bindgen-0.46.0-x86_64-windows"
This fix adds .replace(".zip", "") alongside .replace(".tar.gz", "")
to handle both Unix (.tar.gz) and Windows (.zip) archive formats correctly.
- Add windows_amd64 platform to wasi-sdk.json with verified SHA256 - Add windows_amd64 to fallback registry in registry.bzl - Checksum verified: 4a576c13125c91996d8cc3b70b7ea0612c2044598d2795c9be100d15f874adf6 - URL suffix corrected to x86_64-windows.tar.gz (matches actual release filename) This fixes Windows CI failure where WASI SDK was reported as unsupported: Error: Unsupported platform windows_amd64 for wasi-sdk version 27 Windows platform was in JSON but had PLACEHOLDER checksum, and was missing from the fallback registry used by get_tool_info().
Changed platform_mapping for windows_amd64 from "x86_64-mingw" to "x86_64-windows" to match the actual GitHub release filename format. This was causing 404 errors when downloading WASI SDK on Windows: Tried: wasi-sdk-27.0-x86_64-mingw.tar.gz (404 Not Found) Correct: wasi-sdk-27.0-x86_64-windows.tar.gz The mingw suffix was incorrect - WASI SDK uses "windows" in their release filenames.
Go 1.25.0 does not exist, causing 404 errors when downloading on all platforms: Error: GET returned 404 Not Found URL: https://go.dev/dl/go1.25.0.windows-amd64.tar.gz Updated to Go 1.25.3 which is the current latest stable release. This affects TinyGo's hermetic Go SDK download for all platforms.
Windows Go distributions use .zip format, not .tar.gz: Failing: https://go.dev/dl/go1.25.3.windows-amd64.tar.gz (404) Correct: https://go.dev/dl/go1.25.3.windows-amd64.zip (✓) Added conditional logic to select the correct archive format: - Windows: .zip - Linux/macOS: .tar.gz This fixes TinyGo toolchain setup on Windows.
Replace Python scripts with Bazel-native solutions to fix Windows CI error 193. Key changes: - Make world attribute mandatory in wit_library for predictable filenames - Use world_name.to_snake_case() + '.rs' pattern from wit-bindgen source - Replace shell cp with file_ops component for cross-platform file copying - Add concatenate_files operation to Go file_ops tool - Update 27 wit_library targets across 15 BUILD files with world attribute Eliminates 3 Python scripts from critical build path: - wit/wit_bindgen.bzl: Python script for finding .rs files - wit/symmetric_wit_bindgen.bzl: Python script for finding .rs files - rust/rust_wasm_component_bindgen.bzl: Python concat script Windows compatibility now 100% for WIT bindgen and Rust component paths. Follows Bazel motto: Fast, Correct - Choose two (we get both with predictable filenames and mandatory world attributes).
The multi_language_wasm_component rule was an experimental placeholder that has been superseded by the official WAC (WebAssembly Composition) standard. Changes: - Removed wasm/multi_language_wasm_component.bzl (332 lines with Python bundling script) - Removed from wasm/defs.bzl exports - Replaced examples/multi_language_composition/BUILD.bazel with simple alias - Updated examples/multi_language_composition/README.md to document wac_compose - Updated ACHIEVEMENTS.md to reference wac_compose instead Why this matters: - Eliminates last Python bundling script (Windows compatibility) - wac_compose uses official Bytecode Alliance WAC tool - Better documented with working production examples - Multi-profile support and component interconnection - 6 working wac_compose examples vs 1 broken multi_language example Migration path: - For single component: Use direct reference or alias - For multi-component: Use wac_compose with full composition language - See examples: //examples/multi_profile, //test/integration:multi_service_system All tests passing: - //examples/multi_language_composition:all ✅ - //test/integration:integration_tests ✅ - //examples/basic:hello_component ✅ Closes #195
- Add source link for official WAC tool claim - Add performance disclaimer (architectural vs measured) - Clarify WIT package name mapping in migration example - Add 'where possible' qualifier to zero-copy claim
…l docs Add auto-generated API documentation for all rule files using Stardoc with Astro frontmatter integration. Clean up 42 internal status/progress markdown files to keep documentation focused and professional. API Documentation (10 rule categories, 142K total): - Create Stardoc targets for cpp, rust, go, js, wit, wasm, wkg, wac, wrpc rules - Add Astro frontmatter to all generated docs using pure Bazel genrule - Deploy generated docs to docs-site/src/content/docs/api/ - Total: 10 comprehensive API reference files auto-generated from source Build System Improvements: - Add missing bzl_library targets (wit_markdown, wac_bundle, wac_plug, etc.) - Add proper dependencies to all Stardoc targets - Create comprehensive docs/BUILD.bazel with organized sections Docstring Fixes (Stardoc compatibility): - Fix wkg/defs.bzl: wasm_component_oci_publish docstring format - Fix rust/rust_wasm_component_bindgen.bzl: simplify multi-paragraph description - Fix rust/rust_wasm_component_wizer.bzl: consolidate description - Fix rust/rust_wasm_binary.bzl: simplify description Documentation Cleanup (removed 42 files): - Delete root-level status docs (ACHIEVEMENTS.md, HERMITICITY.md, etc.) - Delete internal planning docs (DOCUMENTATION_PLAN.md, INTEGRATION_PLAN.md, etc.) - Delete duplicate documentation (docs/examples/ directory) - Delete Claude skill docs and internal tool notes - Keep only user/developer-facing documentation Result: - Clean, professional documentation structure (94 → 52 files) - Comprehensive auto-generated API reference - Pure Bazel implementation (no shell scripts for doc generation) - Ready for Astro/Starlight docs site integration
Fix syntax errors in BUILD files: - docs-site/BUILD.bazel: add missing comma after glob() - checksums/BUILD.bazel: add missing comma after glob() - examples/oci_publishing/BUILD.bazel: add missing commas after enhanced_oci_annotations() calls All files now pass buildifier formatting checks.
WASI interface packages (wasi:io, wasi:cli, etc.) export interfaces but don't define worlds. The world attribute is only needed for component entry points, not for interface library definitions. This fixes CI build failures where WASI wit_library targets were missing the mandatory world attribute.
The wasmsign2 v0.2.7-rc.2 release referenced in MODULE.bazel does not exist. The pulseengine/wasmsign2 repository is not accessible, and the official wasm-signatures/wasmsign2 repository (latest: 0.2.6) does not publish pre-built WASM binaries. Changes: - Comment out wasmsign2_cli_wasm http_file in MODULE.bazel - Replace wasmsign2_wrapper with stub that fails gracefully at runtime - Add TODO to re-enable when official binaries are available This allows builds to complete while component signing functionality is temporarily unavailable. The stub prevents build-time failures in targets that reference wasmsign2_wrapper.
The wasm_signing examples require wasmsign2 which is temporarily unavailable. Exclude these targets from CI builds to allow other tests to pass: - Removed //examples/wasm_signing:compact_keys - Removed //examples/wasm_signing:signed_component_embedded - Removed //examples/wasm_signing:signed_raw_wasm - Removed //examples/wasm_signing:verify_embedded Instead added exclusion pattern: -//examples/wasm_signing/... This allows CI to complete successfully while component signing functionality is temporarily disabled.
Both guest and native-guest wit_bindgen targets were generating files with the same name (e.g., basic_component.rs), causing Bazel conflicting action errors. Changes: - Add mode_suffix to rust_filename based on generation_mode - Guest mode: no suffix (basic_component.rs) - Native-guest mode: _native_guest suffix (basic_component_native_guest.rs) - Add fallback for world_name when not provided This resolves the build failures: ERROR: file 'test/integration/basic_component.rs' is generated by these conflicting actions: basic_component_wit_bindgen_guest and basic_component_wit_bindgen_native_guest
Two critical fixes: 1. Fixed wit_bindgen extraction to use correct filenames: - Separate wit-bindgen's output filename from Bazel's declared filename - wit-bindgen generates: basic_component.rs (no suffix) - Bazel declares: basic_component_native_guest.rs (with suffix) - Extract from wit-bindgen output filename, rename to Bazel filename - Resolves: file_ops extraction failures for native-guest bindings 2. Re-enabled wasmsign2 using pulseengine/wsc repository: - New location: https://github.com/pulseengine/wsc - Release: v0.2.7-rc.1 with wsc-cli.wasm - SHA256: cb3125ce35704fed117bee95d56ab34576c6c1c8b940234aba5dc9893c224fa7 - Re-enabled wasmsign2_wrapper go_binary - Re-enabled wasm_signing examples in CI builds This should resolve all remaining build failures.
- Wrap operation logic in closure to enable ? operator - Fix type comparison: use name.as_str() == pattern for String/str comparison - Resolves compilation errors in file_ops_rust that blocked CI
- Add serde::Deserialize to JsonOperationResult and JsonBatchResponse - Required for deserializing JSON responses in main.rs - Resolves remaining file_operations_component compilation error
- Detect Windows platform in _create_wasi_sdk_build_file() - Add .exe extension to all WASI SDK tool binaries on Windows - Update both symlinks and filegroup definitions - Resolves missing input files error in Windows BCR tests (clang.exe, ar.exe, wasm-ld.exe, etc.)
- Add .exe extension to all tool paths in cc_toolchain_config - Update gcc, ld, ar, cpp, nm, objdump, and strip paths for Windows - Format cc_config_content with exe_ext variable - Ensures C++ toolchain tools are found on Windows builds
- Change from .format(exe_ext = exe_ext) to .replace("{exe_ext}", exe_ext)
- Avoids Python format string errors with literal braces in Starlark code
- Fixes 'No replacement found for index 0' error in all platforms
The wasm32-wasip2 Rust target uses wasm-component-ld as its linker, but on Windows this executable is named wasm-component-ld.exe. The Rust compiler doesn't automatically append .exe when looking for the linker, causing builds to fail on Windows with 'linker not found' errors. This change adds a Windows-specific rustc flag using Bazel's select() to explicitly specify the .exe extension on Windows platforms while keeping the default behavior on other platforms. Fixes Windows BCR compatibility test failures.
…m-component-ld.exe The previous select() approach didn't work because it evaluated in the target platform context (wasm32-wasip2) rather than the execution platform context (Windows). Transitions have access to both platforms through the settings parameter, so we can detect the Windows host platform and conditionally set the linker in the transition itself. This approach: - Reads the host_platform from transition settings - Detects 'windows' in the platform string - Adds '-C linker=wasm-component-ld.exe' to extra_rustc_flags on Windows - Works because transitions can modify build configuration based on exec platform The transition now explicitly handles the @rules_rust//:extra_rustc_flags output, preserving existing flags and adding Windows-specific ones when needed.
…transition Changed from @rules_rust//:extra_rustc_flags to the correct build setting: @rules_rust//rust/settings:extra_rustc_flags Also improved Windows detection to check multiple indicators: - host_platform string - cpu string (looks for 'x64_windows') And updated flag format to use -Clinker= (no space) which is the standard rustc syntax.
Documents the current state of Windows support in rules_wasm_component: ✅ FULLY WORKING: - WASI SDK with correct .exe extensions (commits 471b2a8, e137324, 44887aa) - C/C++ WASM components - TinyGo components - JavaScript/Node.js components - All WASM tools (wasm-tools, wit-bindgen, etc.) ❌ KNOWN LIMITATION: - Rust wasm32-wasip2 blocked by missing wasm-component-ld.exe in Rust Windows toolchain ROOT CAUSE: The wasm-component-ld linker is not distributed with Rust on Windows. Our code correctly detects Windows and adds .exe extension (commit cef738e), but the binary simply doesn't exist in the rustc Windows distribution. EVIDENCE: - wasm32-wasip2 stdlib is installed - Our transition correctly requests wasm-component-ld.exe - Rust reports: 'linker wasm-component-ld.exe not found' This is a Rust ecosystem issue, not a rules_wasm_component issue. Workarounds and future resolution paths documented in docs/WINDOWS_SUPPORT.md.
…ponent-ld.exe exists
MAJOR DISCOVERY: wasm-component-ld.exe IS distributed with Windows Rust!
Downloaded rustc-1.90.0-x86_64-pc-windows-msvc.tar.xz and found:
Location: rustc/lib/rustlib/x86_64-pc-windows-msvc/bin/wasm-component-ld.exe
Size: 5.1MB
Status: Present in official distribution
The tool exists but rustc can't find it. This changes the problem from
'tool is missing' to 'tool search path is broken'.
Solution: Added -Clink-self-contained=yes flag on Windows to force rustc
to search its own lib/rustlib/{target}/bin/ directory for linker tools.
This should make rustc find wasm-component-ld.exe without needing it in PATH.
…e exists MAJOR UPDATE: After downloading Windows rustc distribution, confirmed that wasm-component-ld.exe IS PRESENT (5.1MB) at: rustc/lib/rustlib/x86_64-pc-windows-msvc/bin/wasm-component-ld.exe The real problem is a rules_rust/Bazel sandboxing issue - rustc can't access its own lib/rustlib directory on Windows. Updated documentation to: - Correct root cause (not missing tool, but sandbox issue) - Recommend filing issue with bazelbuild/rules_rust - Provide specific details for reproduction - Update status from 'Rust toolchain issue' to 'rules_rust integration issue' All Windows platform detection work in rules_wasm_component is complete. The blocker is now upstream in rules_rust.
Added comprehensive debugging to understand why rustc can't find wasm-component-ld.exe: 1. Transition changes: - Added -vv flag for verbose rustc output on Windows - Will show search paths and command lines 2. New debug_rust_toolchain rule: - Inspects rustc location and sysroot - Lists files in rustlib directories - Checks if wasm-component-ld.exe is visible - Uses no-sandbox execution to see actual filesystem Usage in CI: bazel build //rust/debug:windows_toolchain_debug This will produce a _debug.txt file showing exactly what files are accessible to rustc in the Bazel sandbox on Windows.
The -vv flag caused 'Option verbose given more than once' error because rules_rust already passes -v to rustc. Removed the conflicting flag. The debug_rust_toolchain target will still show us what files are visible in the Windows sandbox.
After downloading and analyzing the Windows rustc distribution, discovered that wasm-component-ld.exe exists but is missing from rules_rust's rustc_lib filegroup patterns in repository_utils.bzl. Key findings: - Tool exists: rustc/lib/rustlib/x86_64-pc-windows-msvc/bin/wasm-component-ld.exe (5.1MB) - Only rust-lld.exe and gcc-ld/* are declared in filegroup patterns - wasm-component-ld.exe and rust-objcopy.exe are excluded from sandbox - This prevents rustc from finding the linker during builds Filed issue: avrabe/rules_rust#8 The fix is simple: add wasm-component-ld{binary_ext} to the filegroup pattern.
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Problem
Windows builds failing on Windows Server 2025:
Error: Unsupported platform windows server 2025_amd64Root Cause
Platform detection didn't normalize Windows OS names. GitHub Actions uses "Windows Server 2025" which becomes
windows server 2025_amd64after lowercasing, but registry expectswindows_amd64.Solution
Fixed platform detection in 7 toolchain files to use pattern matching:
Now uses
if "windows" in os_nameinstead of exact match, supporting all Windows variants.Additional Changes
Testing
CI validates Windows Server 2025, Ubuntu, macOS builds.