Get started with the Fuchsia SDK

This guide provides step-by-step instructions on setting up the Fuchsia SDK development environment on your host machine. The guide then walks you through the basic workflows of building, running, debugging, and testing Fuchsia components using the Fuchsia SDK.

Important: The Fuchsia SDK is in active development. At the moment, Fuchsia does not support general public usage of the Fuchsia SDK. The APIs in the SDK are subject to change without notice.

Complete the following sections:

  1. Prerequisites
  2. Clone the SDK samples repository
  3. Start the emulator
  4. Build and run the sample component
  5. View symbolized logs
  6. Debug the sample component
  7. Inspect components
  8. Run tests

Found an issue? Please let us know{:.external}.

1. Prerequisites {:#prerequisites}

This guide requires that your host machine meets the following criteria:

  • A Linux machine. (macOS is not supported yet.)
  • Has at least 15 GB of storage space.
  • Supports KVM{:.external} (Kernel Virtual Machine) for running a QEMU{:.external}-based emulator.
  • IPv6 is enabled.
  • Git{:.external} is installed.

2. Clone the SDK samples repository {:#clone-the-sdk-samples-repository}

Clone the SDK samples repository{:.external} on your host machine. This repository contains the Bazel-based Fuchsia SDK and sample components.

Note: Support for installing the SDK by itself, without a samples repository, is planned. See this ticket.

The tasks include:

  • Bootstrap the SDK samples repository.
  • Download the SDK toolchain to initialize the SDK environment.
  • Verify that you can run ffx commands.

Do the following:

  1. In a terminal, change to your home directory:

    Note: This guide uses the home directory ($HOME) as a base directory. This is where a new work directory (fuchsia-getting-started) will be created for this guide. You may also select a different base directory (for instance, cd $HOME/my-fuchsia-project).

    cd $HOME
    
  2. Clone the Fuchsia samples repository:

    git clone https://fuchsia.googlesource.com/sdk-samples/getting-started fuchsia-getting-started --recurse-submodules
    

    This creates a new directory named fuchsia-getting-started, which clones the content of the SDK samples repository.

  3. Go to the new directory:

    cd fuchsia-getting-started
    
  4. Run the bootstrap script to install Bazel and other required dependencies:

    scripts/bootstrap.sh
    
  5. Download the SDK toolchain:

    tools/bazel build @fuchsia_sdk//:fuchsia_toolchain_sdk
    

    This command may take a few minutes to download all the tools and dependencies, such as Bazel build rules, Clang{:.external} and Fuchsia IDK (which includes the ffx tool).

    When finished successfully, it prints output similar to the following in the end:

    $ tools/bazel build @fuchsia_sdk//:fuchsia_toolchain_sdk
    Starting local Bazel server and connecting to it...
    INFO: Analyzed target @fuchsia_sdk//:fuchsia_toolchain_sdk (2 packages loaded, 2 targets configured).
    INFO: Found 1 target...
    Target @fuchsia_sdk//:fuchsia_toolchain_sdk up-to-date (nothing to build)
    INFO: Elapsed time: 26.344s, Critical Path: 0.02s
    INFO: 1 process: 1 internal.
    INFO: Build completed successfully, 1 total action
    
  6. To verify that you can use the ffx tool in your environment, run the following command:

    tools/ffx sdk version
    

    This command prints output similar to the following:

    $ tools/ffx sdk version
    9.20220807.3.1
    

    At this point, you only need to confirm that you can run ffx commands without error. (However for your information, the output above shows the version 9.20220807.3.1, which indicates that this SDK was built and published on August 7, 2022.)

    Note: To ensure that you’re using the right version of ffx during development, consider updating your PATH to include the SDK‘s tools directory (for instance, export PATH="$PATH:$HOME/fuchsia-getting-started/tools"). However, if you don’t wish to update your PATH, ensure that you specify the relative path to this ffx tool (tools/ffx) whenever you run ffx commands.

3. Start the emulator {:#start-the-emulator}

Start the Fuchsia emulator on the host machine. This guide uses an instance of the Fuchsia emulator as the target device for running and testing Fuchsia software. And to be able to supply new Fuchsia software to the target device, you also need to start the Fuchsia package server on the host machine.

The tasks include:

  • Download one of Fuchsia's prebuilt images from Google Cloud Storage.
  • Start the Fuchsia emulator to run the downloaded Fuchsia prebuilt image.
  • Set the emulator instance as the default target device.
  • Verify that various ffx commands can connect to the emulator instance.
  • Start the Fuchsia package server.
  • Register the system package repository to the emulator instance.

Do the following:

  1. Download the latest Fuchsia Workstation prebuilt image for the emulator (workstation_eng.qemu-x64):

    tools/ffx product-bundle get workstation_eng.qemu-x64 --repository workstation-packages
    

    This command may take a few minutes to download the image and product metadata.

    Note: If the product-bundle command fails with an error due to multiple product bundle instances or SDK versions, clean up the environment before proceeding.

    Once the download is finished, the ffx product-bundle get command creates a local Fuchsia package repository named workstation-packages on your host machine. This package repository hosts additional system packages for this Workstation prebuilt image. Later in Step 12 you’ll register this package repository to the emulator instance.

  2. Stop all running emulator instances:

    tools/ffx emu stop --all
    
  3. Start a new Fuchsia emulator instance:

    tools/ffx emu start workstation_eng.qemu-x64 --headless
    

    This command starts a headless emulator instance running the Workstation prebuilt image.

    When the instance is up and running, the command prints output similar to the following:

    $ tools/ffx emu start workstation_eng.qemu-x64 --headless
    Creating SSH key pair: /home/alice/.ssh/fuchsia_ed25519
    Writing authorized_keys file: /home/alice/.ssh/fuchsia_authorized_keys
    Logging to "/home/alice/.local/share/Fuchsia/ffx/emu/instances/fuchsia-emulator/emulator.log"
    Waiting for Fuchsia to start (up to 60 seconds)...........
    Emulator is ready.
    
  4. Verify that the new emulator instance is running:

    tools/ffx emu list
    

    This command prints output similar to the following:

    $ tools/ffx emu list
    [Active]    fuchsia-emulator
    
  5. Verify that the emulator instance is detected as a device:

    tools/ffx target list
    

    This command prints output similar to the following:

    $ tools/ffx target list
    NAME                SERIAL       TYPE                        STATE      ADDRS/IP            RCS
    fuchsia-emulator    <unknown>    Unknown                     Product    [172.16.243.142]    Y
    
  6. Set this emulator instance to be the default device:

    tools/ffx target default set fuchsia-emulator
    

    This command exits silently without output.

  7. Verify that the default device is set:

    tools/ffx target default get
    

    This command prints output similar to the following:

    $ tools/ffx target default get
    fuchsia-emulator
    
  8. To verify that you can establish an SSH connection to the emulator instance, run the following command:

    Note: To retrieve detailed device information, the ffx target show command uses Fuchsia-specific SSH keys to make an SSH connection to the device.

    tools/ffx target show
    

    This command prints output similar to the following:

    $ tools/ffx target show
    Target:
        Name: "fuchsia-emulator"
        SSH Address: "127.0.0.1:42577"
    Board:
        Name: "default-board"
        Revision: "1"
        Instruction set: "x64"
    Device:
        ...
    Build:
        Version: "9.20220807.3.1"
        Product: "workstation_eng"
        Board: "qemu-x64"
        Commit: "2022-08-07T20:02:13+00:00"
    Last Reboot:
        Graceful: "false"
        Reason: "Cold"
    ...
    

    The example output above shows that the target device is running a workstation_eng.qemu-x64 prebuilt image whose version is 9.20220807.3.1.

  9. Verify that you can stream the device logs:

    tools/ffx log
    

    This command prints output similar to the following:

    $ tools/ffx log
    ...
    [33.698][core/cobalt][cobalt,fidl_service,core][I] LocalAggregation: Enabling local aggregation.
    [33.698][core/cobalt][cobalt,fidl_service,core][I] ClearcutV1ShippingManager: Disabling observation uploading.
    [34.818][core/network/netstack][netstack,DHCP][W] client.go(692): ethp0004: recv timeout waiting for dhcpOFFER; retransmitting dhcpDISCOVER
    [34.818][core/network/netstack][netstack,DHCP][I] client.go(891): ethp0004: send dhcpDISCOVER from :68 to 255.255.255.255:67 on NIC:2 (broadcast_flag=false ciaddr=false)
    [35.654][core/remote-control][remote_control,remote-control][I] attempting to connect hub_path="/discovery_root/children/bootstrap/resolved/expose/fuchsia.diagnostics.LogSettings"
    ...
    

    Press CTRL+C to exit.

  10. Start the Fuchsia package server:

    tools/ffx repository server start
    

    This command prints output similar to the following:

    $ tools/ffx repository server start
    ffx repository server is listening on [::]:8083
    
  11. Check the list of Fuchsia package repositories available on your host machine:

    tools/ffx repository list
    

    This command prints output similar to the following:

    $ tools/ffx repository list
    +-----------------------+------+-------------------------------------------------------------------------------------------------+
    | NAME                  | TYPE | EXTRA                                                                                           |
    +=======================+======+=================================================================================================+
    | workstation-packages* | pm   | /home/alice/.local/share/Fuchsia/ffx/pbms/4751486831982119909/workstation_eng.qemu-x64/packages |
    +-----------------------+------+-------------------------------------------------------------------------------------------------+
    

    Notice a package repository (workstation-packages) is created for the Workstation prebuilt image.

  12. Register the workstation-packages package repository to the target device:

    tools/ffx target repository register -r workstation-packages --alias fuchsia.com --alias chromium.org
    

    This command exits silently without output.

4. Build and run the sample component {:#build-and-run-the-sample-component}

Build and run the C++ Hello World component{:.external} included in the SDK samples repository. Components are the basic unit of executable software on Fuchsia.

The tasks include:

  • Build and run the sample Hello World component.
  • Make a change to the component.
  • Repeat the build and run steps.
  • Verify the change.

Do the following:

  1. Build and run the sample component:

    tools/bazel run --config=fuchsia_x64 //src/hello_world:pkg.component
    

    When the build is successful, this command generates build artifacts in a temporary Fuchsia package repository, which is then removed after the component runs.

    The command prints output similar to the following:

    $ tools/bazel run --config=fuchsia_x64 //src/hello_world:pkg.component
    INFO: Build options --copt, --cpu, --crosstool_top, and 1 more have changed, discarding analysis cache.
    INFO: Analyzed target //src/hello_world:pkg.component (53 packages loaded, 1647 targets configured).
    INFO: Found 1 target...
    Target //src/hello_world:pkg.component up-to-date:
      bazel-bin/src/hello_world/pkg.component_run_component.sh
    INFO: Elapsed time: 86.842s, Critical Path: 2.20s
    INFO: 126 processes: 101 internal, 24 linux-sandbox, 1 local.
    INFO: Build completed successfully, 126 total actions
    INFO: Build completed successfully, 126 total actions
    added repository bazel.pkg.component
    URL: fuchsia-pkg://bazel.pkg.component/hello_world#meta/hello_world.cm
    Moniker: /core/ffx-laboratory:hello_world
    Creating component instance...
    Starting component instance...
    Success! The component instance has been started.
    
  2. Check the status of the hello_world component:

    tools/ffx component show hello_world
    

    This command prints output similar to the following:

    $ tools/ffx component show hello_world
                   Moniker:  /core/ffx-laboratory:hello_world
                       URL:  fuchsia-pkg://bazel.pkg.component/hello_world#meta/hello_world.cm
               Instance ID:  None
                      Type:  CML Component
           Component State:  Resolved
     Incoming Capabilities:  /svc/fuchsia.logger.LogSink
      Exposed Capabilities:
               Merkle root:  8575a55f5b894b0ca284786bf0f6c80f09a26d9a3a53157b4826a210d2f58f20
           Execution State:  Stopped
    

    The output shows that the hello_world component has run and is now terminated (Stopped).

  3. Verify the Hello, World! message in the device logs:

    tools/ffx log --filter hello_world dump
    

    This command prints output similar to the following:

    $ tools/ffx log --filter hello_world dump
    ...
    [pkg-resolver][pkg-resolver][I] Fetching blobs for fuchsia-pkg://bazel.pkg.component/hello_world: [
        98ac8f77f52618766aec226c11e2bbd894637d18583b80b29b21938b75d6633a,
    ]
    [pkg-resolver][pkg-resolver][I] resolved fuchsia-pkg://bazel.pkg.component/hello_world as fuchsia-pkg://bazel.pkg.component/hello_world to cca474915d74415e302017f567b557c034eed50019d6881f52db916756292662 with TUF
    {{ '<strong>' }}[core/ffx-laboratory:hello_world][][I] Hello, World!{{ '</strong>' }}
    
  4. Use a text editor to edit the src/hello_world/hello_world.cc file, for example:

    nano src/hello_world/hello_world.cc
    
  5. Change the message to "Hello again, World!".

    The main() method should look like below:

    int main() {
      {{ '<strong>' }}std::cout << "Hello again, World!\n";{{ '</strong>' }}
      return 0;
    }
    
  6. Save the file and exit the text editor.

  7. Build and run the sample component again:

    tools/bazel run --config=fuchsia_x64 //src/hello_world:pkg.component
    
  8. Verify the Hello again, World! message in the device logs:

    tools/ffx log --filter hello_world dump
    

    This command prints output similar to the following;

    $ tools/ffx log --filter hello_world dump
    ...
    [pkg-resolver][pkg-resolver][I] Fetching blobs for fuchsia-pkg://bazel.pkg.component/hello_world: [
        98ac8f77f52618766aec226c11e2bbd894637d18583b80b29b21938b75d6633a,
    ]
    [pkg-resolver][pkg-resolver][I] resolved fuchsia-pkg://bazel.pkg.component/hello_world as fuchsia-pkg://bazel.pkg.component/hello_world to cca474915d74415e302017f567b557c034eed50019d6881f52db916756292662 with TUF
    {{ '<strong>' }}[core/ffx-laboratory:hello_world][][I] Hello again, World!{{ '</strong>' }}
    

5. View symbolized logs {:#view-symbolized-logs}

Examine the symbolized logs (that is, human readable stack traces) of a crashed component.

The tasks include:

  • Update the sample component to crash when it's started.
  • Build and run the sample component, which generates and registers the debug symbols of the component.
  • Verify that the crashed component's logs are in symbolized format.

Do the following:

  1. Use a text editor to edit the src/hello_world/hello_world.cc file, for example:

    nano src/hello_world/hello_world.cc
    
  2. Just above the line return 0;, add the following line:

    abort();
    

    The main() method should look like below:

    int main() {
      std::cout << "Hello again, World!\n";
      {{ '<strong>' }}abort();{{ '</strong>' }}
      return 0;
    }
    

    This update will cause the component to crash immediately after printing a message.

  3. Save the file and exit the text editor.

  4. Build and run the sample component:

    tools/bazel run --config=fuchsia_x64 //src/hello_world:pkg.component
    

    Building a component automatically generates and registers the component’s debug symbols in your development environment.

  5. For newly registered symbols to be used in your environment, restart the ffx daemon:

    Note: This is a temporary workaround. This issue is being tracked in Issue 94614{:.external}.

    tools/ffx daemon stop
    

    A new instance of the ffx daemon starts the next time you run a ffx command.

  6. Verify that the sample component's crash stack is symbolized in the kernel logs:

    tools/ffx log --kernel
    

    This command prints output similar to the following:

    $ tools/ffx log --kernel
    ...
    [174978.449][klog][klog][I] [[[ELF module #0x6 "libzircon.so" BuildID=5679a47f32c6fa7b 0x422808b26000]]]
    [174978.449][klog][klog][I] [[[ELF module #0x7 "libc.so" BuildID=1c3e8dded0fc94eb 0x428049099000]]]
    [174978.450][klog][klog][I]    #0    0x00004280490fd74b in abort() ../../zircon/third_party/ulib/musl/src/exit/abort.c:7 <libc.so>+0x6474b sp 0x11d191bcf70
    {{ '<strong>' }}[174978.450][klog][klog][I]    #1    0x000001d56b552047 in main() src/hello_world/hello_world.cc:9 <<VMO#32996646=blob-a4c56246>>+0x2047 sp 0x11d191bcf80{{ '</strong>' }}
    [174978.450][klog][klog][I]    #2    0x00004280490fcef2 in start_main(const start_params*) ../../zircon/third_party/ulib/musl/src/env/__libc_start_main.c:140 <libc.so>+0x63ef2 sp 0x11d191bcfa0
    [174978.450][klog][klog][I]    #3    0x00004280490fd145 in __libc_start_main(zx_handle_t, int (*)(int, char**, char**)) ../../zircon/third_party/ulib/musl/src/env/__libc_start_main.c:215 <libc.so>+0x64145 sp 0x11d191bcff0
    [174978.450][klog][klog][I]    #4    0x000001d56b552011 in _start(zx_handle_t) ../../zircon/system/ulib/c/Scrt1.cc:7 <<VMO#32996646=blob-a4c56246>>+0x2011 sp 0x42d5c7089fe0
    [174978.450][klog][klog][I]    #5    0x0000000000000000 is not covered by any module sp 0x42d5c7089ff0
    [174978.457][klog][klog][I] KERN: terminating process 'hello_world.cm' (32996655)
    

    Verify that the lines in the kernel logs show the exact filenames and line numbers (for example, main() src/hello_world/hello_world.cc:9) that might've caused the component to crash.

    Press CTRL+C to exit.

6. Debug the sample component {:#debug-the-sample-component}

Launch the Fuchsia debugger (zxdb) for debugging the sample component, which is now updated to crash when it's started.

The tasks include:

  • Start the Fuchsia debugger and connect it to the emulator instance.
  • Attach the debugger to the sample component.
  • Set a breakpoint.
  • Run the sample component and step through the code.

Do the following:

  1. Start the Fuchsia debugger:

    tools/ffx debug connect
    

    This command automatically connects the debugger to the default target device, which is the emulator instance.

    When connected to the device, this command starts the zxdb terminal, for example:

    $ tools/ffx debug connect
    Connecting (use "disconnect" to cancel)...
    Connected successfully.
    👉 To get started, try "status" or "help".
    [zxdb]
    
  2. In the zxdb terminal, attach the debugger to the hello_world.cm component:

This command prints output similar to the following:

[zxdb] attach hello_world.cm
Waiting for process matching "hello_world.cm".
Type "filter" to see the current filters.
  1. In the zxdb terminal, set a breakpoint at the main() method:

This command prints output similar to the following:

[zxdb] break main
Created Breakpoint 1 @ main
Pending: No current matches for location. It will be matched against new
         processes and shared libraries.
  1. In a different terminal, run the sample component:

    Note: In this new terminal, make sure that you change to the same work directory (for instance, cd $HOME/fuchsia-getting-started).

    tools/bazel run --config=fuchsia_x64 //src/hello_world:pkg.component
    

    In the zxdb terminal, the sample component is paused at the breakpoint:

    Attached Process 1 state=Running koid=17658651 name=hello_world.cm
    Downloading symbols...
    Breakpoint 1 now matching 1 addrs for main
    Could not load symbols for "<vDSO>" because there was no mapping for build ID "1dbd2861a642d61b".
    Symbol downloading complete. 0 succeeded, 1 failed.
    🛑 on bp 1, 2 main()  hello_world.cc:8
        6
        7 int main() {
       8   std::cout << "Hello again, World!\n";
        9   abort();
       10   return 0;
    [zxdb]
    

    Note: You can re-build and re-run your component as many times as you want, but do not need to restart the debugger or run attach again. The debugger will preserve your breakpoints and continue watching for future processes called hello_world.cm.

  2. In the new terminal, monitor device logs for the hello_world component:

    tools/ffx log --filter hello_world
    

    This comment prints output similar to the following:

    $ tools/ffx log --filter hello_world
    ...
    [pkg-resolver][pkg-resolver][I] Fetching blobs for fuchsia-pkg://bazel.pkg.component/hello_world: [
        98ac8f77f52618766aec226c11e2bbd894637d18583b80b29b21938b75d6633a,
    ]
    [pkg-resolver][pkg-resolver][I] resolved fuchsia-pkg://bazel.pkg.component/hello_world as fuchsia-pkg://bazel.pkg.component/hello_world to cca474915d74415e302017f567b557c034eed50019d6881f52db916756292662 with TUF
    
    

    Notice the Hello again, World! line is not printed yet.

  3. In the zxdb terminal, use next to step through the code:

In the zxdb terminal, the code get executed line by line, for example:

...
🛑 on bp 1 main()  hello_world.cc:8
    6 
    7 int main() {
   8   std::cout << "Hello again, World!\n";
    9   abort();
   10   return 0;
[zxdb] {{ '<strong>'}}next{{ '</strong>'}}
🛑 main()  hello_world.cc:9
    7 int main() {
    8   std::cout << "Hello again, World!\n";
   9   abort();
   10   return 0;
   11 }

In the device logs terminal, verify that the Hello again, World! line is now printed:

[core/ffx-laboratory:hello_world][][I] Hello again, World!
  1. To exit the zxdb terminal, type exit or press Ctrl-D.

    This causes the component to finish the execution of the rest of the code.

    Note: For more information on usages and best practices on zxdb, see the zxdb user guide.

7. Inspect components {:#inspect-components}

Retrieve a component‘s data exposed by Fuchsia’s Inspect API. This data can be any set of specialized information that a Fuchsia component is programmed to collect while it is running on the device.

Note: For a component to collect and expose inspect data, the implementation of inspect operations and data types must be placed in the component’s code. Developers use this inspect feature to collect and expose information that will be helpful for debugging the component or the system. For details, see Fuchsia component inspection overview.

The tasks include:

  • Scan the list of components on the device that expose inspect data (for example, the bootstrap/archivist component).
  • Scan the list of selectors provided by the bootstrap/archivist component.
  • Inspect a specific set of data from the bootstrap/archivist component.

Do the following:

  1. View the list of components on the device that expose inspect data:

    tools/ffx inspect list
    

    This command prints output similar to the following:

    $ tools/ffx inspect list
    <component_manager>
    bootstrap/archivist
    bootstrap/driver_manager
    bootstrap/fshost
    bootstrap/fshost/blobfs
    bootstrap/fshost/fxfs
    ...
    core/ui/scenic
    core/vulkan_loader
    core/wlancfg
    core/wlandevicemonitor
    core/wlanstack
    

    Notice that the bootstrap/archivist component is on the list.

  2. View all available selectors for the bootstrap/archivist component:

    tools/ffx inspect selectors bootstrap/archivist
    

    This command prints output similar to the following:

    $ tools/ffx inspect selectors bootstrap/archivist
    bootstrap/archivist:root/archive_accessor_stats/all/inspect/batch_iterator/get_next:errors
    bootstrap/archivist:root/archive_accessor_stats/all/inspect/batch_iterator/get_next:requests
    bootstrap/archivist:root/archive_accessor_stats/all/inspect/batch_iterator/get_next:responses
    ...
    

    Each of these selectors represents a different type of data you can inspect.

  3. Inspect the bootstrap/archivist component for the recent events data:

    tools/ffx inspect show bootstrap/archivist:root/events/recent_events
    

    This command prints output similar to the following:

    $ tools/ffx inspect show bootstrap/archivist:root/events/recent_events
    bootstrap/archivist:
      metadata:
        filename = fuchsia.inspect.Tree
        component_url = fuchsia-boot:///#meta/archivist.cm
        timestamp = 705335717538
      payload:
        root:
          events:
            recent_events:
              361:
                @time = 6272744049
                event = component_stopped
                moniker = core/trace_manager/cpuperf_provider
              362:
                @time = 6283370267
                event = log_sink_requested
                moniker = core/session-manager
              ...
              556:
                @time = 415796882099
                event = log_sink_requested
                moniker = core/debug_agent
              557:
                @time = 453898419738
                event = component_started
                moniker = core/ffx-laboratory:hello_world
              558:
                @time = 453899964568
                event = log_sink_requested
                moniker = core/ffx-laboratory:hello_world
              559:
                @time = 453900332656
                event = log_sink_requested
                moniker = core/ffx-laboratory:hello_world
              560:
                @time = 495458923475
                event = component_stopped
                moniker = core/ffx-laboratory:hello_world
    

    This data records all the events triggered by components on the device so far.

8. Run tests {:#run-tests}

Run tests on the device by launching test components, which are included in the SDK samples repository{:.external}.

The tasks include:

  • Build and run the sample test components.
  • Update one of the tests to fail.
  • Verify the failure in the test results.

Do the following:

  1. Build and run the sample test components:

    tools/bazel test --config=fuchsia_x64 --test_output=all //src/hello_world:test_pkg
    

    This command runs all the tests in the Hello World component’s test package (hello_world:test_pkg{:.external}).

    The command prints output similar to the following:

    $ tools/bazel test --config=fuchsia_x64 --test_output=all //src/hello_world:test_pkg
    INFO: Analyzed target //src/hello_world:test_pkg (10 packages loaded, 568 targets configured).
    INFO: Found 1 test target...
    INFO: From Testing //src/hello_world:test_pkg:
    ==================== Test output for //src/hello_world:test_pkg:
    Running 2 test components...
    added repository bazel.test.pkg.hello.gtest
    Running test 'fuchsia-pkg://bazel.test.pkg.hello.gtest/hello_test#meta/hello_gtest_autogen_cml.cm'
    [RUNNING]    HelloTest.BasicAssertions
    [stdout - HelloTest.BasicAssertions]
    Running main() from gmock_main.cc
    Example stdout.
    [PASSED]    HelloTest.BasicAssertions
    
    1 out of 1 tests passed...
    fuchsia-pkg://bazel.test.pkg.hello.gtest/hello_test#meta/hello_gtest_autogen_cml.cm completed with result: PASSED
    added repository bazel.test.pkg.hello.test
    Running test 'fuchsia-pkg://bazel.test.pkg.hello.test/hello_test#meta/hello_test_autogen_cml.cm'
    [RUNNING]    main
    [stdout - main]
    Example stdout.
    [PASSED]    main
    
    1 out of 1 tests passed...
    fuchsia-pkg://bazel.test.pkg.hello.test/hello_test#meta/hello_test_autogen_cml.cm completed with result: PASSED
    2 test components passed.
    ================================================================================
    Target //src/hello_world:test_pkg up-to-date:
      bazel-bin/src/hello_world/test_pkg_test_package.sh
    INFO: Elapsed time: 16.866s, Critical Path: 9.80s
    INFO: 105 processes: 46 internal, 56 linux-sandbox, 3 local.
    INFO: Build completed successfully, 105 total actions
    //src/hello_world:test_pkg                                               PASSED in 3.3s
    
    Executed 1 out of 1 test: 1 test passes.
    INFO: Build completed successfully, 105 total actions
    
  2. Use a text editor to edit the src/hello_world/hello_gtest.cc file, for example:

    nano src/hello_world/hello_gtest.cc
    
  3. Replace EXPECT_STRNE() with EXPECT_STREQ():

    The test should look like below:

    TEST(HelloTest, BasicAssertions) {
      std::cout << "Example stdout." << std::endl;
    
      // Expect two strings not to be equal.
      {{ '<strong>' }}EXPECT_STREQ("hello", "world");{{ '</strong>' }}
      // Expect equality.
      EXPECT_EQ(7 * 6, 42);
    }
    

    This change will cause the GoogleTest{:.external} (hello_gtest) to fail.

  4. Save the file and exit the text editor.

  5. To verify that the updated test now fails, build and run the hello_gtest component:

    tools/bazel test --config=fuchsia_x64 --test_output=all //src/hello_world:test_pkg.hello_gtest
    

    This command prints output similar to the following:

    $ tools/bazel test --config=fuchsia_x64 --test_output=all //src/hello_world:test_pkg.hello_gtest
    INFO: Analyzed target //src/hello_world:test_pkg.hello_gtest (0 packages loaded, 0 targets configured).
    INFO: Found 1 test target...
    FAIL: //src/hello_world:test_pkg.hello_gtest (see /home/alice/.cache/bazel/_bazel_alice/ea119f1048230a864836be3d62fead2c/execroot/__main__/bazel-out/x86_64-fastbuild/testlogs/src/hello_world/test_pkg.hello_gtest/test.log)
    INFO: From Testing //src/hello_world:test_pkg.hello_gtest:
    ==================== Test output for //src/hello_world:test_pkg.hello_gtest:
    added repository bazel.test.pkg.hello.gtest
    Running test 'fuchsia-pkg://bazel.test.pkg.hello.gtest/hello_test#meta/hello_gtest_autogen_cml.cm'
    [RUNNING]   HelloTest.BasicAssertions
    [stdout - HelloTest.BasicAssertions]
    Running main() from gmock_main.cc
    Example stdout.
    src/hello_world/hello_gtest.cc:14: Failure
    Expected equality of these values:
      "hello"
      "world"
    [FAILED]   HelloTest.BasicAssertions
    
    Failed tests: HelloTest.BasicAssertions
    0 out of 1 tests passed...
    fuchsia-pkg://bazel.test.pkg.hello.gtest/hello_test#meta/hello_gtest_autogen_cml.cm completed with result: FAILED
    One or more test runs failed.
    Tests failed.
    ================================================================================
    Target //src/hello_world:test_pkg.hello_gtest up-to-date:
      bazel-bin/src/hello_world/test_pkg.hello_gtest_run_component.sh
    INFO: Elapsed time: 3.810s, Critical Path: 3.42s
    INFO: 11 processes: 2 internal, 6 linux-sandbox, 3 local.
    INFO: Build completed, 1 test FAILED, 11 total actions
    //src/hello_world:test_pkg.hello_gtest                                   FAILED in 1.8s
      /home/alice/.cache/bazel/_bazel_alice/ea119f1048230a864836be3d62fead2c/execroot/__main__/bazel-out/x86_64-fastbuild/testlogs/src/hello_world/test_pkg.hello_gtest/test.log
    
    INFO: Build completed, 1 test FAILED, 11 total actions
    

Congratulations! You're now all set with the Fuchsia SDK!

Next steps {:#next-steps}

Learn more about the Fuchsia platform and tools in Fuchsia SDK Fundamentals.

Appendices

Clean up the environment {:#clean-up-the-environment}

If you run into a problem while following this guide and decide to start over from the beginning, consider running the commands below to clean up your development environment (that is, to clean up directories, build artifacts, downloaded files, symlinks, configuration settings, and more).

Remove the package repositories created in this guide:

tools/ffx repository remove workstation-packages
tools/ffx repository server stop

Remove all existing configurations and data of ffx:

tools/ffx daemon stop
rm -rf $HOME/.local/share/Fuchsia/ffx

When Bazel fails to build, try the commands below:

Caution: Running bazel clean or deleting the $HOME/.cache/bazel directory deletes all the artifacts downloaded by Bazel, which can be around 4 GB. This means Bazel will need to download those dependencies again the next time you run bazel build.

tools/bazel clean --expunge
tools/bazel shutdown && rm -rf $HOME/.cache/bazel

Remove the fuchsia-getting-started directory and its artifacts:

Caution: If the SDK samples repository is cloned to a different location than $HOME/fuchsia-getting-started, adjust the directory path in the command below. Be extremely careful with the directory path when you run the rm -rf <DIR> command.

rm -rf $HOME/fuchsia-getting-started

Other clean up commands:

killall ffx
killall pm

Update the firewall rules {:#update-the-firewall-rules}

When you launch the sample component (for instance, using the command tools/bazel run), you might run into an issue where the command hangs for a long time and eventually fails with the following error:

Lifecycle protocol could not start the component instance: InstanceCannotResolve

In that case, you may need to update the firewall rules on your host machine.

If you’re using the ufw firewall, run the following commands:

sudo ufw allow proto tcp from fe80::/10 to any port 8083 comment 'Fuchsia Package Server'
sudo ufw allow proto tcp from fc00::/7 to any port 8083 comment 'Fuchsia Package Server'

However, for other non-ufw-based firewalls, you will need to ensure that port 8083 is available for the Fuchsia package server.