flutter % et help build          

Usage: et build [arguments]
-h, --help                               Print this usage information.

    --[no-]rbe                           Enable pre-configured remote build execution.
                                         (defaults to on)
    --build-strategy                     How to prefer remote or local builds.

          [auto] (default)               Prefer remote builds and fallback silently to local builds.
          [local]                        Use local builds.
                                         No internet connection is required.
          [remote]                       Use remote builds.
                                         If --build-strategy is not specified, the build will fail.

-j, --concurrency                        How many jobs to run in parallel.

flutter % et help build --verbose

Usage: et build [arguments]
-h, --help                                                 Print this usage information.

    --[no-]lto                                             Whether LTO should be enabled for a
                                                           build.
                                                           If omitted, defaults to the
                                                           configuration's specified value, which is
                                                           typically (but not always) --no-lto.
    --[no-]rbe                                             Enable pre-configured remote build
                                                           execution.
                                                           
                                                           Google employees can follow the
                                                           instructions at
                                                           https://flutter.dev/to/engine-rbe to
                                                           enable RBE, which can parallelize builds
                                                           and reduce build times on faster internet
                                                           connections.
                                                           (defaults to on)
    --build-strategy                                       How to prefer remote or local builds.

          [auto] (default)                                 Prefer remote builds and fallback
                                                           silently to local builds.
          [local]                                          Use local builds.
                                                           No internet connection is required.
          [remote]                                         Use remote builds.
                                                           If --build-strategy is not specified, the
                                                           build will fail.

-j, --concurrency                                          How many jobs to run in parallel.

flutter % ./tools/gn --help
usage: gn [-h] [--unoptimized] [--enable-unittests] [--no-enable-unittests]
          [--runtime-mode {debug,profile,release,jit_release}] [--dart-debug]
          [--no-dart-version-git-info] [--full-dart-debug]
          [--dart-optimization-level DART_OPTIMIZATION_LEVEL]
          [--target-os {android,ios,mac,linux,fuchsia,wasm,win}] [--android]
          [--android-cpu {arm,x64,x86,arm64}] [--ios] [--mac] [--mac-cpu {x64,arm64}] [--simulator]
          [--linux] [--fuchsia] [--wasm] [--wasm-use-dwarf] [--web] [--windows]
          [--linux-cpu {x64,x86,arm64,arm}] [--fuchsia-cpu {x64,arm64}]
          [--windows-cpu {x64,arm64,x86}] [--simulator-cpu {x64,arm64}]
          [--arm-float-abi {hard,soft,softfp}] [--backtrace] [--no-backtrace]
          [--build-engine-artifacts] [--no-build-engine-artifacts] [--rbe] [--no-rbe]
          [--rbe-server-address RBE_SERVER_ADDRESS]
          [--rbe-exec-strategy {local,remote,remote_local_fallback,racing}]
          [--rbe-dial-timeout RBE_DIAL_TIMEOUT] [--rbe-platform RBE_PLATFORM] [--rbe-dir RBE_DIR]
          [--goma] [--no-goma] [--xcode-symlinks] [--no-xcode-symlinks] [--depot-tools DEPOT_TOOLS]
          [--lto] [--no-lto] [--clang] [--no-clang] [--clang-static-analyzer]
          [--no-clang-static-analyzer] [--target-sysroot TARGET_SYSROOT]
          [--target-toolchain TARGET_TOOLCHAIN] [--target-triple TARGET_TRIPLE]
          [--operator-new-alignment OPERATOR_NEW_ALIGNMENT] [--macos-enable-metal] [--enable-vulkan]
          [--enable-fontconfig] [--enable-vulkan-validation-layers] [--embedder-for-target]
          [--coverage] [--out-dir OUT_DIR] [--target-dir TARGET_DIR] [--full-dart-sdk]
          [--no-full-dart-sdk] [--build-canvaskit] [--ide IDE] [--allow-deprecated-api-calls]
          [--disable-desktop-embeddings] [--build-glfw-shell] [--no-build-glfw-shell]
          [--build-embedder-examples] [--no-build-embedder-examples] [--stripped] [--no-stripped]
          [--prebuilt-dart-sdk] [--no-prebuilt-dart-sdk] [--use-mallinfo2] [--enable-impeller-3d]
          [--malioc-path MALIOC_PATH] [--impeller-cmake-example] [--slimpeller] [--asan] [--lsan]
          [--msan] [--tsan] [--ubsan] [--fstack-protector] [--darwin-extension-safe] [--verbose]
          [--gn-args GN_ARGS] [--use-glfw-swiftshader]

A script to run `gn gen`.

optional arguments:
  -h, --help            show this help message and exit
  --unoptimized
  --enable-unittests    Force enable building unit test binaries.
  --no-enable-unittests
                        Force disable building unit test binaries.
  --runtime-mode {debug,profile,release,jit_release}
  --dart-debug          Enables assertions in the Dart VM. Does not affect optimization levels. If
                        you need to disable optimizations in Dart, use --full-dart-debug
  --no-dart-version-git-info
                        Set by default; if unset, turns off the dart SDK git hash check
  --full-dart-debug     Implies --dart-debug and also disables optimizations in the Dart VM making it
                        easier to step through VM code in the debugger.
  --dart-optimization-level DART_OPTIMIZATION_LEVEL
                        The default optimization level for the Dart VM runtime.
  --target-os {android,ios,mac,linux,fuchsia,wasm,win}
  --android
  --android-cpu {arm,x64,x86,arm64}
  --ios
  --mac
  --mac-cpu {x64,arm64}
  --simulator
  --linux
  --fuchsia
  --wasm
  --wasm-use-dwarf      Embed dwarf debugging info in the output module instead of using sourcemap
                        files.
  --web
  --windows
  --linux-cpu {x64,x86,arm64,arm}
  --fuchsia-cpu {x64,arm64}
  --windows-cpu {x64,arm64,x86}
  --simulator-cpu {x64,arm64}
  --arm-float-abi {hard,soft,softfp}
  --backtrace           Whether OS support exists for collecting backtraces.
  --no-backtrace
  --build-engine-artifacts
                        Build the host-side development artifacts.
  --no-build-engine-artifacts
                        Do not build the host-side development artifacts.
  --rbe
  --no-rbe
  --rbe-server-address RBE_SERVER_ADDRESS
                        The reproxy serveraddress
  --rbe-exec-strategy {local,remote,remote_local_fallback,racing}
                        The RBE execution strategy.
  --rbe-dial-timeout RBE_DIAL_TIMEOUT
                        The timeout for connecting to the local reproxy server.
  --rbe-platform RBE_PLATFORM
                        The RBE "platform" string. This is used to identify remote platform settings
                        like the docker image to use to run the command.
  --rbe-dir RBE_DIR     The location of the reclient binaries.
  --goma
  --no-goma
  --xcode-symlinks      Set to true for builds targeting macOS or iOS when using RBE. If set,
                        symlinks to the Xcode provided sysroot and SDKs will be created in a
                        generated folder, which will avoid potential backend errors in Fuchsia RBE.
                        Instead of specifying the flag on each invocation the
                        FLUTTER_GOMA_CREATE_XCODE_SYMLINKS environment variable may be set to 1 to
                        achieve the same effect.
  --no-xcode-symlinks
  --depot-tools DEPOT_TOOLS
                        Depot tools provides an alternative location for gomacc in
                        /path/to/depot_tools/.cipd_bin
  --lto
  --no-lto
  --clang
  --no-clang
  --clang-static-analyzer
  --no-clang-static-analyzer
  --target-sysroot TARGET_SYSROOT
  --target-toolchain TARGET_TOOLCHAIN
  --target-triple TARGET_TRIPLE
  --operator-new-alignment OPERATOR_NEW_ALIGNMENT
  --macos-enable-metal
  --enable-vulkan
  --enable-fontconfig
  --enable-vulkan-validation-layers
  --embedder-for-target
  --coverage
  --out-dir OUT_DIR     Root out directory. Target specific gn files will be generated in ${out-dir}/
  --target-dir TARGET_DIR
                        Use the specified name for target out directory. By default this tool
                        determines one.
  --full-dart-sdk       include trained dart2js and dartdevc snapshots. Enable only on steps that
                        create an SDK
  --no-full-dart-sdk
  --build-canvaskit     build canvaskit from source (DEPRECATED: use ninja targets to select what to
                        build)
  --ide IDE             The IDE files to generate using GN. Use `gn gen help` and look for the --ide
                        flag to see supported IDEs. If this flag is not specified, a platform
                        specific default is selected.
  --allow-deprecated-api-calls
                        Turns off warnings about the usage of deprecated APIs.
  --disable-desktop-embeddings
                        Do not include desktop embeddings in the build.
  --build-glfw-shell    Build the GLFW shell on supported platforms where it is not built by default.
  --no-build-glfw-shell
                        Do not build the GLFW shell on platforms where it is built by default.
  --build-embedder-examples
                        Build the example embedders using the Embedder API.
  --no-build-embedder-examples
                        Do not build the example embedders using the Embedder API.
  --stripped            Strip debug symbols from the output. This defaults to true and has no effect
                        on iOS.
  --no-stripped
  --prebuilt-dart-sdk   Whether to use a prebuilt Dart SDK instead of building one. This defaults to
                        true and is enabled on CI.
  --no-prebuilt-dart-sdk
  --use-mallinfo2       Use mallinfo2 to collect malloc stats.
  --enable-impeller-3d  Enables experimental 3d support.
  --malioc-path MALIOC_PATH
                        The path to the malioc tool.
  --impeller-cmake-example
                        Do not run GN. Instead configure the Impeller cmake example build.
  --slimpeller          Enable optimizations that attempt to reduce binary size of the Flutter engine
                        by assuming only the Impeller rendering engine is supported.See
                        [go/slimpeller-dashboard](https://github.com/orgs/flutter/projects/21) for
                        details.
  --asan
  --lsan
  --msan
  --tsan
  --ubsan
  --fstack-protector    Whether the -fstack-protector flag should be passed unconditionally.
  --darwin-extension-safe
                        Whether the produced Flutter.framework is app extension safe. Only for iOS.
  --verbose
  --gn-args GN_ARGS     Additional gn args to be passed to gn. If you need to use this, it should
                        probably be another switch in //flutter/tools/gn.
  --use-glfw-swiftshader
                        Forces glfw to use swiftshader.