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Bazel Documents

This is an index of all documents for Bazel.

There are two kinds:

  • Design docs that are subject to the workflow described below
  • Live documents for which the workflow is not a good fit

Design doc workflow

New proposals follow the design process and are sent for review as a GitHub discussion.

State diagram of the design process

    ur: Under review
    Draft --> ur
    ur --> Approved
    Approved --> Implemented
    Draft --> Dropped
    ur --> Dropped
    Approved --> Dropped
    classDef success fill:#ded
    classDef failure fill:#fcc
    class Implemented success
    class Dropped failure

Live documents

Last updated Title Author(s) alias
2023-09-26 Bazelbuild Repositories Maintenance Guide @comius and @meteorcloudy
2023-08-30 Bazel Proto Rules @comius
2023-08-01 Problems with Bazel's code coverage collection @c-mita
2023-07-27 A Guide to Skyframe StateMachines @aoeui
2022-02-17 The Bazel codebase @lberki

Design docs

Under review

Last updated Title Author(s) alias Category
2023-09-07 A true repository cache @Wyverald External Repositories
2023-08-08 Standard exec configurations @gregestren Configurability
2023-08-08 bazel mod fix @fmeum External dependencies
2023-08-08 Inheritance of Target Incompatibility @fmeum Platforms, Configurability
2023-06-30 Fingerprinting Starlark Functions @brandjon Starlark and actions
2023-06-16 Extending Bazel rules @comius Starlark Rules
2023-06-15 Integrated bzl_library @brandjon Starlark
2023-05-31 subrule: Decomposing Starlark rules @comius Starlark Rules
2023-05-04 Directory watching API for repo rules @Wyverald External Repositories
2023-03-17 C/C++ standard resolution for Bazel modules @fmeum C++, External Repositories
2023-03-17 More accurate cquery @gregestren Configurability
2022-10-17 Dependency adapters for virtual targets @vdye Bazel


Last updated Title Author(s) alias Category
2023-01-18 Modular cc toolchains @silvergasp CC toolchain rules
2020-10-09 Adding http mirror to accelerate repos downloading @yancl External Repositories
2021-06-25 Better Starlark analysis unit tests @hvadehra Starlark
2022-04-25 Extend expand_template() API to reduce retained memory @hvadehra Starlark
2022-04-29 @since(version) annotations in documentation. @aiuto Documentation


Last updated Title Author(s) alias Category
2023-08-14 Platform-based flags @katre Platforms
2023-08-08 Standard platform transitions @katre Platforms
2023-06-12 Remote Output Service: place bazel-out/ on a FUSE file system @EdSchouten Remote Execution
2023-03-21 Bazel feature detection in Starlark @Wyverald General, Starlark Rules
2023-03-14 REPO.bazel @Wyverald External Repositories
2023-03-07 Build Stamping API for Starlark rules @buildbreaker2021 Starlark Rules
2023-01-23 Remote Cache Eviction for Build without the Bytes @coeuvre Remote Execution
2022-10-11 Renaming applicable_licenses @aiuto Configuration
2023-01-30 Transitive static libraries @fmeum C++
2022-12-15 Bzlmod lockfile @salmasamy Bazel, External Repositories
2022-05-12 Bzlmod External Dependencies Inspection Tool @andyrinne12 External Repositories
2022-05-11 Deprecating managed_directories @lberki External Repositories
2021-02-15 External directory reshuffling @lberki External Repositories
2021-02-15 C++ rules skylark migration plan @mhlopko C++
2019-05-08 Android Native to Starlark Migration @timpeut Android
2018-08-14 Decoupling android_ndk_repository from Bazel @jin Android
2018-07-31 Splitting large BEP events @buchgr Build Event Protocol


Last updated Title Author(s) alias Category
2022-09-05 Automatic exec groups for toolchains @comius @kotlaja Configurability
2023-03-20 Automatic use_repo fixups for module extensions @fmeum External Repositories
2022-08-17 Locating runfiles with Bzlmod @fmeum External Repositories, Bazel
2023-06-13 Credential Helpers for Bazel @Yannic External Repositories
2022-03-18 proto_common module @comius Proto Rules
2021-06-23 Improving native.existing_rules @tetromino, @brandjon Build Language
2021-06-09 Aspects Propagating other Aspects @messa Starlark
2021-04-22 Custom constructors for providers @brandjon Build Language
2021-03-24 Java common refactoring @comius Java rules
2020-12-22 Injecting Starlark Values Into Builtins @brandjon Starlark
2021-03-06 OSS License Declarations @aiuto Product
2021-02-15 Rules for software license compliance @aiuto License Rules, Bazel
2023-03-31 Optional Toolchains @katre Configurability
2022-05-25 Canonical label literals @Wyverald External Repositories
2022-03-07 Representing repeatable Starlark flags as config.string_list @fmeum Configurability, Build Language
2022-01-14 Proposal for subpackages built-in helper function @kkress Bazel
2021-08-02 Bazel Central Registry Policies and Procedures @meteorcloudy External Repositories
2021-03-06 Remote Persistent Workers [@ulfjack]
2021-03-06 Rules authors SIG @alexeagle Community
2021-02-18 Require ProtoInfo for proto_lang_toolchain#blacklisted_protos @Yannic Protobuf
2021-02-16 Selecting Between Python 2 and 3 @brandjon Python
2021-02-16 Remote Downloads @EricBurnett, @jmillikin, @sstriker External Repositories
2021-02-16 Starlark Directory Expansion in Args MapEach @haileiyu Starlark
2021-02-16 Test execution on Windows without Bash @laszlocsomor Windows
2021-02-15 Toolchain resolution using configuration flags @comius Configurability
2021-02-15 Configured Query Starlark Output @c-parsons Configurability, Starlark
2021-02-15 Proposal: new format ‘flag_per_line’ for Args @vmaverick Starlark
2021-02-15 cquery somepath: easy mode @gregestren Configurability
2021-02-15 Automatically migrating maven_jar to rules_jvm_external @jin External Repositories
2021-02-15 Target-level execution properties @agoulti Configurability
2021-02-15 Bazel Starlark API: add ctx.resolve_tools @laszlocsomor Starlark
2021-02-15 Auto-configured Host Platform @katre Configurability
2021-02-15 Multiplex persistent worker @borkaehw Bazel
2021-02-15 Starlark Build Configuration @juliexxia, @gregestren Configurability
2021-02-15 Crosstool in Skylark @scentini, @mhlopko C++
2021-02-15 Declared Providers @dslomov, @laurentlb Starlark
2021-02-15 Java Platformization @comius Configurability
2021-02-15 Starlark Shorthand Flag Mapping @WarkahScott Configurability
2021-02-15 Measuring Configuration Overhead @gregestren Configurability
2021-02-15 Action Groups (Multi-Toolchain Resolution) @juliexxia Configurability
2021-02-15 Common Bazel Constraints @gregestren Configurability
2021-02-15 Starlark Build Configurations - Parameterized-Transitions API @juliexxia Configurability
2021-02-15 Partial C++ Starlark API @oquenchil C++
2021-02-15 Crosstool in Skylark @mhlopko C++
2021-02-15 Shrinking the Bazel binary @buchgr, @meistert Bazel
2021-02-15 External C/C++ libraries rules @ichern Bazel
2021-02-15 Bazel Runfiles Libraries @laszlocsomor Bazel
2021-02-15 Name resolution @laurentlb Starlark
2020-10-28 Keepalived remote execution @coeuvre Remote Execution
2020-10-19 Bazel External Dependencies Overhaul @meteorcloudy, @philwo, @Wyverald External Repositories
2020-09-30 Toolchain Transition Migration @katre Configurability
2020-09-30 Toolchain Transitions @katre Configurability
2020-09-30 Passing Toolchain Context across Dependencies @katre Configurability
2020-05-13 Execution Transitions @katre Configurability
2020-05-13 Old Flags to Platform Migration @aragos Configurability
2019-12-20 Incompatible Target Skipping @AustinSchuh, @gregestren Configurability
2019-12-17 cquery somepath: easy mode @gregestren Configurability
2019-12-17 Exposing Target Platform Constraints @katre Configurability
2019-10-24 Visibility for source files @aehlig Build API
2019-04-22 Move //tools/build_defs/pkg to rules_pkg @aiuto Bazel
2019-05-10 Bazel with NPM package manager @ichern External Repositories
2019-05-27 Authentication for @aehlig External Repositories
2019-04-29 Forcing non-cache-hits in the repository cache @aehlig External Repositories
2019-04-05 Handling download failures @aehlig External Repositories
2018-12-14 Versioned Documentation @jin Documentation
2018-11-26 Update Download Functions in repository_ctx @dkelmer External Repositories
2018-11-14 Platform Inheritance @katre Configurability
2018-11-09 Config Setting Chaining @gregestren Configurability
2018-10-29 Progress reporting for external repositories @aehlig External Repositories
2018-11-10 Symlinks in Remote Execution @buchgr Remote Execution
2018-08-27 Args Directory Support @tomlu Starlark
2018-08-20 Skylark API to the C++ toolchain @mhlopko C++
2018-08-03 Skyframe threading model @tomlu Skyframe
2018-07-13 Bazel hashing of external directory output @aehlig External Repositories
2018-05-24 Unified Configuration Transitions @gregestren Configurability
2018-04-26 Per-Rule Execution Platform Constraints @katre Configurability
2017-10-06 Dynamic Bazel Configurations @gregestren Configurability
2017-03-03 Label-keyed String Dictionary Type for Build Attributes @serynth Configurability
2017-01-20 Aspect required providers @tomlu, @dslomov Starlark
2017-01-20 Aspects-on-aspects @dslomov Starlark
2016-10-18 Invalidation of remote repositories @damienmg External Repositories
2016-10-11 Distribution Artifact for Bazel @aehlig Release
2016-09-30 Central cache for external repositories @jin External Repositories
2016-09-05 Building Python on Windows @meteorcloudy Python, Windows
2016-06-21 Specifying environment variables @aehlig Bazel
2016-06-02 Sandboxing @philwo Bazel
2016-05-26 Implementing Beautiful Error Messages (Loading Phase) @laurentlb Bazel
2016-05-23 Beautiful error messages @laurentlb Bazel
2016-04-18 Parameterized Skylark Aspects @dslomov, lindleyf Starlark
2016-02-16 Generating C++ crosstool with a Skylark Remote Repository @damienmg Toolchains
2015-07-02 Skylark Remote Repositories @damienmg External repositories


Last updated Title Author(s) alias Category
2023-06-21 Integrated bzl_library @brandjon Starlark
2022-02-18 Coding guidelines for Starlark rules @comius Starlark Rules
2019-07-11 Load Bazel Protobuf rules from @rules_proto @Yannic Protobuf
2022-07-07 Enabling Global exec_groups @susinmotion Configurability
2021-06-17 Starlark fail(errorcode="") @aiuto Documentation / Event Stream
2023-03-31 Execution Platforms vs. Strategies @katre and @aragos Configurability
2021-02-18 Toolchainifying proto rules @Yannic Protobuf
2023-03-30 Guidance for Rules Authors how to deal with Bazel versions / upgrades @philwo Bazel
2022-11-16 Platforms on Targets @katre Configuration
2021-07-21 Monorepo Toolchain Registration @katre Toolchains
2021-02-16 Semantics of the expansion of Labels @aehlig External Repositories
2021-02-16 Propagate tags from the targets to actions @ishikhman Bazel, Starlark
2021-02-16 Remote Repository Cache jmillikin External Repositories
2021-02-16 Moving Skylark out of Bazel @brandjon Starlark
2021-02-16 Dependency Discovery Proposal @stevebillings External Repositories
2021-02-16 s/skydoc/stardoc/g: a plan @jin Documentation
2021-02-16 Experimental Content-Based Output Paths @gregestren Configurability
2021-02-15 Managing Breaking Changes in Bazel @dslomov Community
2021-02-15 Separating Build API from Bazel @c-parsons Starlark
2021-02-15 Improved Command Line Reporting @cvcal Bazel
2021-02-15 Bazel External Dependencies Roadmap @dslomov External Repositories
2021-02-15 Aspects Propagating Other Aspects @lberki Build API
2021-02-15 Mandatory load() statements in BUILD files @lberki Starlark
2021-02-15 Visibility for implicit attributes @aehlig Build API
2021-02-15 Structured Compiler Diagnostics @illicitonion Build Event Protocol, Build API
2021-02-15 Replacing native <lang>_proto_library rules with Starlark @Yannic Protobuf
2021-02-15 Always dirty repository rules @ichern External Repositories
2021-02-15 Design for a Python Toolchain @brandjon Python
2021-02-15 Bazel Federation @dslomov, @laurentlb Community
2021-02-15 On custom shell toolchain for Bazel Starlark rules @ichern Toolchains, Starlark
2021-02-15 Recursive Workspaces @aehlig External Repositoires
2021-02-15 Resource auto-tuning via flags @jmmv Performance
2021-02-15 Repository Remapping Revisited @dkelmer External Repositories
2021-02-15 Bazel Rules Curation @laurentlb Community
2021-02-15 Extending the design of WORKSPACE files @aehlig, @dslomov External Repositories
2021-02-15 Namespaces when using multiple bazel repositories @aehlig, @dslomov External Repositories
2021-02-15 Delaying of load statements @aehlig External Repositories
2021-02-15 Repository rules with multiple return values @aehlig External Repositories
2021-02-15 Diamond Splitting for External Repositories @dslomov External Repositories
2021-02-15 Output Map Madness @brandjon Starlark
2021-02-15 External Repositories: The Future @aehlig, @dslomov External Repositories
2021-02-15 A Brave New World for the Bazel WORKSPACE File @mattmoor, @dslomov, @davidstanke, @damienmg External Repositories
2021-02-15 Garbage Collection for the Repository Cache @aehlig External Repositories
2021-02-15 Saner Skylark Sets @dslomov Starlark
2021-02-15 Customizing the Python Stub Template @brandjon Python
2021-02-15 HTTP downloads with Authorization using .netrc @genrym External Repositories
2021-02-15 Package Validation Proposal @kkress Bazel, Starlark
2020-10-19 Adding a constraint to default target platform @comius Configurability
2020-09-30 Bazel Constraint Equality @aragos Configurability
2020-09-30 Versioned Runtime APIs under Platforms & Toolchains @aragos Configurability
2020-01-16 Starlark project files @robbertvanginkel Bazel, Starlark
2019-08-22 Non-Hermetic Tool Paths in Platforms @aragos Configurability
2019-08-01 Platforms and Strategies @katre Configurability, Execution Strategy
2018-06-14 Platforms and Configurations @katre C++, Starlark
2016-09-19 Recursive WORKSPACE file parsing @kchodorow External Repositories
2015-03-06 bazel init a.k.a ./configure for Bazel @damienmg Bazel


Index of all Bazel proposals and design documents




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