starlark

This document provides an overview of the commands and options available under buck2 starlark.

buck2 starlark

Run Starlark operations

Usage: buck2 starlark <COMMAND>

Subcommands:

• lint: Run the Starlark linter.
• typecheck: Run the Starlark typechecker.
• debug-attach: Run the starlark debug adapter protocol server

Common Options:

Common options are documented on the Common Options page.

buck2 starlark lint

Run the Starlark linter.

Usage: buck2 starlark lint [OPTIONS] <PATH>...

Arguments:

• <PATH>

Common Options:

Common options are documented on the Common Options page.

Options:

• --disable-starlark-types Disable runtime type checking in Starlark interpreter.

  This option is not stable, and can be used only locally to diagnose evaluation performance problems.

• --stack Record or show target call stacks.

  Starlark call stacks will be included in duplicate targets error.

  If a command outputs targets (like targets command), starlark call stacks will be printed after the targets.

• --profile-patterns <PROFILE_PATTERNS> Enables profiling for all evaluations whose evaluation identifier matches one of the provided patterns.

  Some examples identifiers: analysis/cell//buck2/app/buck2_action_impl:buck2_action_impl (cfg:linux-x86_64#27ac5723e0c99706) load/cell//build_defs/json.bzl load/prelude//playground/test.bxl load/cell//build_defs/json.bzl@other_cell load_buildfile/fbcode//third-party-buck/platform010/build/ncurses load_packagefile/fbcode//cli/rust/cli_delegate anon_analysis/anon//:_anon_link_rule (anon: 766183dc9b6f680a) (fbcode//buck2/platform/execution:linux-x86_64#08961b14cfb182aa) bxl/prelude//playground/test.bxl:playground

  You can pass --profile-patterns=.* to enable no-op profiling for everything (additionally pass --profile-patterns-mode=none to use no-op profiling to just get a list of all the identifiers).

  The profile results will be written to individual .profile files in <ROOT_OUTPUT>/<data+time>-<uuid>/ where ROOT_OUTPUT comes from the --profile-patterns-output flag. In that directory there will also be a file listing all the identifiers that were profiled.

  Enabling/disabling profiling of an evaluation will invalidate the results of that evaluation and it will be recomputed. In some cases, this will cause other work to also need to be redone (for example, invalidating the result of loading PACKAGE files causes all consumers to be recomputed). But if you keep profiling options consistent between commands, only the work that is otherwise invalidated will be redone (and only for those would profiling results be created).

  You must also pass --profile-patterns-mode and --profile-patterns-output.

• --profile-patterns-output <PATH>

• --profile-patterns-mode <PROFILE_PATTERNS_MODE> Profile mode.

  Memory profiling modes have suffixes either -allocated or -retained.

  -retained means memory kept in frozen starlark heaps after analysis completes. -retained does not work when profiling loading, because no memory is retained after loading and frozen heap is not even created. This is probably what you want when profiling analysis.

  -allocated means allocated memory, including memory which is later garbage collected.

  • Possible values:
    • time-flame
    • heap-allocated
    • heap-retained
    • heap-flame-allocated
    • heap-flame-retained
    • heap-summary-allocated
    • heap-summary-retained
    • statement
    • bytecode
    • bytecode-pairs
    • typecheck
    • coverage
    • none

buck2 starlark typecheck

Run the Starlark typechecker.

Usage: buck2 starlark typecheck [OPTIONS] <PATH>...

Arguments:

• <PATH>

Common Options:

Common options are documented on the Common Options page.

Options:

• --disable-starlark-types Disable runtime type checking in Starlark interpreter.

  This option is not stable, and can be used only locally to diagnose evaluation performance problems.

• --stack Record or show target call stacks.

  Starlark call stacks will be included in duplicate targets error.

  If a command outputs targets (like targets command), starlark call stacks will be printed after the targets.

• --profile-patterns <PROFILE_PATTERNS> Enables profiling for all evaluations whose evaluation identifier matches one of the provided patterns.

  Some examples identifiers: analysis/cell//buck2/app/buck2_action_impl:buck2_action_impl (cfg:linux-x86_64#27ac5723e0c99706) load/cell//build_defs/json.bzl load/prelude//playground/test.bxl load/cell//build_defs/json.bzl@other_cell load_buildfile/fbcode//third-party-buck/platform010/build/ncurses load_packagefile/fbcode//cli/rust/cli_delegate anon_analysis/anon//:_anon_link_rule (anon: 766183dc9b6f680a) (fbcode//buck2/platform/execution:linux-x86_64#08961b14cfb182aa) bxl/prelude//playground/test.bxl:playground

  You can pass --profile-patterns=.* to enable no-op profiling for everything (additionally pass --profile-patterns-mode=none to use no-op profiling to just get a list of all the identifiers).

  The profile results will be written to individual .profile files in <ROOT_OUTPUT>/<data+time>-<uuid>/ where ROOT_OUTPUT comes from the --profile-patterns-output flag. In that directory there will also be a file listing all the identifiers that were profiled.

  Enabling/disabling profiling of an evaluation will invalidate the results of that evaluation and it will be recomputed. In some cases, this will cause other work to also need to be redone (for example, invalidating the result of loading PACKAGE files causes all consumers to be recomputed). But if you keep profiling options consistent between commands, only the work that is otherwise invalidated will be redone (and only for those would profiling results be created).

  You must also pass --profile-patterns-mode and --profile-patterns-output.

• --profile-patterns-output <PATH>

• --profile-patterns-mode <PROFILE_PATTERNS_MODE> Profile mode.

  Memory profiling modes have suffixes either -allocated or -retained.

  -retained means memory kept in frozen starlark heaps after analysis completes. -retained does not work when profiling loading, because no memory is retained after loading and frozen heap is not even created. This is probably what you want when profiling analysis.

  -allocated means allocated memory, including memory which is later garbage collected.

  • Possible values:
    • time-flame
    • heap-allocated
    • heap-retained
    • heap-flame-allocated
    • heap-flame-retained
    • heap-summary-allocated
    • heap-summary-retained
    • statement
    • bytecode
    • bytecode-pairs
    • typecheck
    • coverage
    • none

buck2 starlark debug-attach

Run the starlark debug adapter protocol server

This forwards requests received on stdin to a debug server running in the buck daemon. DAP events and responses are returned from the daemon and sent to this command's stdout.

Usage: buck2 starlark debug-attach [OPTIONS]

Common Options:

Common options are documented on the Common Options page.

Options:

• --disable-starlark-types Disable runtime type checking in Starlark interpreter.

  This option is not stable, and can be used only locally to diagnose evaluation performance problems.

• --stack Record or show target call stacks.

  Starlark call stacks will be included in duplicate targets error.

  If a command outputs targets (like targets command), starlark call stacks will be printed after the targets.

• --profile-patterns <PROFILE_PATTERNS> Enables profiling for all evaluations whose evaluation identifier matches one of the provided patterns.

  Some examples identifiers: analysis/cell//buck2/app/buck2_action_impl:buck2_action_impl (cfg:linux-x86_64#27ac5723e0c99706) load/cell//build_defs/json.bzl load/prelude//playground/test.bxl load/cell//build_defs/json.bzl@other_cell load_buildfile/fbcode//third-party-buck/platform010/build/ncurses load_packagefile/fbcode//cli/rust/cli_delegate anon_analysis/anon//:_anon_link_rule (anon: 766183dc9b6f680a) (fbcode//buck2/platform/execution:linux-x86_64#08961b14cfb182aa) bxl/prelude//playground/test.bxl:playground

  You can pass --profile-patterns=.* to enable no-op profiling for everything (additionally pass --profile-patterns-mode=none to use no-op profiling to just get a list of all the identifiers).

  The profile results will be written to individual .profile files in <ROOT_OUTPUT>/<data+time>-<uuid>/ where ROOT_OUTPUT comes from the --profile-patterns-output flag. In that directory there will also be a file listing all the identifiers that were profiled.

  Enabling/disabling profiling of an evaluation will invalidate the results of that evaluation and it will be recomputed. In some cases, this will cause other work to also need to be redone (for example, invalidating the result of loading PACKAGE files causes all consumers to be recomputed). But if you keep profiling options consistent between commands, only the work that is otherwise invalidated will be redone (and only for those would profiling results be created).

  You must also pass --profile-patterns-mode and --profile-patterns-output.

• --profile-patterns-output <PATH>

• --profile-patterns-mode <PROFILE_PATTERNS_MODE> Profile mode.

  Memory profiling modes have suffixes either -allocated or -retained.

  -retained means memory kept in frozen starlark heaps after analysis completes. -retained does not work when profiling loading, because no memory is retained after loading and frozen heap is not even created. This is probably what you want when profiling analysis.

  -allocated means allocated memory, including memory which is later garbage collected.

  • Possible values:
    • time-flame
    • heap-allocated
    • heap-retained
    • heap-flame-allocated
    • heap-flame-retained
    • heap-summary-allocated
    • heap-summary-retained
    • statement
    • bytecode
    • bytecode-pairs
    • typecheck
    • coverage
    • none