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.

Complete the following sections:

Prerequisites
Clone the SDK samples repository
Start the emulator
Create a local package repository
Build and run the sample component
View symbolized logs
Debug the sample component
Inspect components
Run tests

Found an issue? Please let us know.

1. Prerequisites

Before you begin, complete the prerequisite steps below:

Check host machine requirements
Install dependencies
Generate Fuchsia-specific SSH keys

Check host machine requirements

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 (Kernel Virtual Machine) for running a QEMU-based emulator.
IPv6 is enabled.

Install dependencies

git and bazel need to be installed on the host machine. You need Bazel 5.1 or higher.

Do the following:

Install Git.
Install Bazel – the easiest install option is to download the Bazelisk binary and rename it to bazel in a convenient place on your path.

Generate Fuchsia-specific SSH keys

The ffx tool requires that Fuchsia-specific SSH keys are stored on the host machine for connecting to Fuchsia devices (including the Fuchsia emulator).

To check if your host machine already has Fuchsia SSH keys, do the following:

Scan the $HOME/.ssh directory for Fuchsia SSH keys:
```
ls $HOME/.ssh | grep fuchsia
```

Verify that the following fuchsia_* files are present:

$ ls $HOME/.ssh | grep fuchsia
fuchsia_authorized_keys
fuchsia_ed25519
fuchsia_ed25519.pub

If you don’t see these files, you need to generate Fuchsia SSH keys on the host machine:

Generate a new private and public SSH key pair:

Note: These Fuchsia SSH keys are only used for connecting to Fuchsia devices during development. Generating these SSH keys won't alter your current SSH settings.
```
[[ -f "${HOME}/.ssh/fuchsia_ed25519" ]] || ssh-keygen -P "" -t ed25519 -f "${HOME}/.ssh/fuchsia_ed25519" -C "${USER}@$(hostname -f) Shared SSH Key for Fuchsia"
```

Generate a fuchsia_authorized_keys file:

[[ -f "${HOME}/.ssh/fuchsia_authorized_keys" ]] || ssh-keygen -y -f "${HOME}/.ssh/fuchsia_ed25519" > "${HOME}/.ssh/fuchsia_authorized_keys"

Verify that Fuchsia SSH keys are generated:

ls $HOME/.ssh | grep fuchsia

This command prints output similar to the following:

$ ls $HOME/.ssh | grep fuchsia
fuchsia_authorized_keys
fuchsia_ed25519
fuchsia_ed25519.pub

2. Clone the SDK samples repository

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

The tasks include:

Bootstrap the SDK samples repository.
Verify that you can build the sample components and run ffx commands.

Do the following:

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 (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
```
Clone the Fuchsia samples repository:
```
git clone https://fuchsia.googlesource.com/sdk-samples/getting-started --recurse-submodules
```
This creates a new directory named getting-started, which clones the content of the SDK samples repository.
Go to the new directory:
```
cd getting-started
```
To verify the Fuchsia SDK environment setup, build the sample components:

Note: If it doesn't exist already, the bazel build command below creates the $HOME/.package_repos/sdk-samples directory on your host machine. This directory is used for storing and serving Fuchsia packages in this guide.
```
bazel build --config=fuchsia_x64 //src/hello_world:pkg --publish_to=$HOME/.package_repos/sdk-samples
```
The first build may take a few minutes to download dependencies, such as Clang and Fuchsia IDK (which includes the ffx tool).

When finished successfully, it prints output similar to the following in the end:
```
$ bazel build --config=fuchsia_x64 //src/hello_world:pkg --publish_to=$HOME/.package_repos/sdk-samples
...
INFO: Elapsed time: 70.715s, Critical Path: 1.87s
INFO: 43 processes: 28 internal, 13 linux-sandbox, 2 local.
INFO: Build completed successfully, 43 total actions
```
To verify that you can use the ffx tool in your environment, run the following command:
```
tools/ffx version -v
```
This command prints output similar to the following:
```
$ tools/ffx version -v
ffx:
  abi-revision: 0xA56735A6690E09D8
  api-level: 8
  build-version: 2022-04-25T14:46:40+00:00
  integration-commit-hash: 41e415830c1649b9c09ef570bb3620cf923cdfac
  integration-commit-time: Mon, 25 Apr 2022 14:46:40 +0000

daemon:
  abi-revision: 0xA56735A6690E09D8
  api-level: 8
  build-version: 2022-04-25T14:46:40+00:00
  integration-commit-hash: 41e415830c1649b9c09ef570bb3620cf923cdfac
  integration-commit-time: Mon, 25 Apr 2022 14:46:40 +0000
```
At this point, you only need to confirm that you can run this ffx command without any errors.

Note: To ensure that you’re using the right version of ffx (which needs to match the version of the SDK), consider updating your PATH to include the SDK's tools directory where ffx is located (for instance, export PATH="$PATH:$HOME/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 Fuchsia emulator 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.

Do the following:

Download the latest Fuchsia Workstation prebuilt image for the emulator (workstation.qemu-x64):
```
tools/ffx product-bundle get workstation.qemu-x64
```
This command may take a few minutes to download the image and product metadata.
(Optional) Stop all running emulator instances:
```
tools/ffx emu stop --all
```

Start a new Fuchsia emulator instance:

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

This command starts a headless emulator instance running a Fuchsia prebuilt image.

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

$ tools/ffx emu start workstation.qemu-x64 --headless
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.

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
```

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    [fe80::d4e3:9a5b:c2e:2534%qemu]    Y

Set this emulator instance to be the default device:
```
tools/ffx target default set fuchsia-emulator
```
This command exits silently without output.
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
```
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: "[fe80::9597:e5fb:4746:a7b1%3]:22"
Board:
    Name: "default-board"
    Revision: "1"
    Instruction set: "x64"
Device:
    ...
Build:
    Version: "7.20220330.2.1"
    Product: "workstation"
    Board: "qemu-x64"
    Commit: "2022-03-30T14:02:43+00:00"
Last Reboot:
    Graceful: "false"
    Reason: "Cold"
```
The example output above shows that the target device is running a workstation.qemu-x64 prebuilt image whose version is 7.20220330.2.1 (which indicates that this image was built and published on March 30, 2022).

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.

4. Create a local package repository

Create a local Fuchsia package repository and register it to a Fuchsia device. This package repository is used for storing and serving Fuchsia packages in this guide.

The tasks include:

Create a new Fuchsia package repository.
Start the Fuchsia package server.
Register the new local package repository to the target device (that is, the emulator instance).
Register the system package repository to the target device.

Do the following:

Create a new Fuchsia package repository (and map it to the $HOME/.package_repos/sdk-samples directory):

Note: The $HOME/.package_repos/sdk-samples directory is created on your host machine when you run the bazel build command for the first time in the Clone the SDK samples repository section.
```
tools/ffx repository add-from-pm -r fuchsiasamples.com $HOME/.package_repos/sdk-samples
```
This command prints output similar to the following:
```
$ tools/ffx repository add-from-pm -r fuchsiasamples.com $HOME/.package_repos/sdk-samples
added repository fuchsiasamples.com
```

Verify that the new package repository (fuchsiasamples.com) is created:

tools/ffx repository list

This command prints output similar to the following:

$ tools/ffx repository list
+----------------------+------+-----------------------------------------------+
| NAME                 | TYPE | EXTRA                                         |
+======================+======+===============================================+
| fuchsiasamples.com   | pm   | /home/alice/.package_repos/sdk-samples        |
+----------------------+------+-----------------------------------------------+
| workstation.qemu-x64 | pm   | /home/alice/.local/share/Fuchsia/.../packages |
+----------------------+------+-----------------------------------------------+

The workstation.qemu-x64 repository is created when you run the ffx product-bundle get command (previously in the Start the emulator section above). This repository contains additional system packages for the workstation.qemu-x64 prebuilt image.

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

Register the fuchsiasamples.com repository to the target device (that is, the emulator instance):
```
tools/ffx target repository register -r fuchsiasamples.com
```
This command exits silently without output.
Register the workstation.qemu-x64 repository to the target device as fuchsia.com:
```
tools/ffx target repository register -r workstation.qemu-x64 --alias fuchsia.com
```
This command exits silently without output.

Verify that the repositories are registered to the target device:

tools/ffx target repository list

This command prints output similar to the following:

$ tools/ffx target repository list
+----------------------+----------------------+
| REPO                 | TARGET               |
+======================+======================+
| fuchsiasamples.com   | fuchsia-emulator     |
+----------------------+----------------------+
| workstation.qemu-x64 | fuchsia-emulator     |
|                      |   alias: fuchsia.com |
+----------------------+----------------------+

5. Build and run the sample component

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

The tasks include:

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

Do the following:

Build the sample component:
```
bazel build --config=fuchsia_x64 //src/hello_world:pkg --publish_to=$HOME/.package_repos/sdk-samples
```
When the build is successful, it publishes the build artifacts to the $HOME/.package_repos/sdk-samples directory, which is associated with your new local Fuchsia package repository.

Run the sample component:

tools/ffx component run "fuchsia-pkg://fuchsiasamples.com/hello_world#meta/hello_world.cm"

This command prints output similar to the following:

$ tools/ffx component run "fuchsia-pkg://fuchsiasamples.com/hello_world#meta/hello_world.cm"
URL: fuchsia-pkg://fuchsiasamples.com/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.

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://fuchsiasamples.com/hello_world#meta/hello_world.cm
                  Type: CML dynamic component
       Component State: Resolved
 Incoming Capabilities: fuchsia.logger.LogSink
                        pkg
           Merkle root: b44de670cf30c77c55823af0fea67d19e0fabc86ddd0946646512be12eeb8dc0
       Execution State: Stopped

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

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
...
[1702.331][core/pkg-resolver][pkg-resolver][I] Fetching blobs for fuchsia-pkg://fuchsiasamples.com/hello_world: []
[1702.331][core/pkg-resolver][pkg-resolver][I] resolved fuchsia-pkg://fuchsiasamples.com/hello_world as fuchsia-pkg://fuchsiasamples.com/hello_world to dbdc177180730f521849484c7a0e11dbe763b75804a7d1b97158a668b463526c with TUF
[1702.405][core/ffx-laboratory:hello_world][][I] Hello, World!

Use a text editor to edit the src/hello_world/hello_world.cc file, for example:
```
nano src/hello_world/hello_world.cc
```
Change the message to "Hello again, World!".

The main() method should look like below:
```
int main() {
  std::cout << "Hello again, World!\n";
  return 0;
}
```
Save the file and exit the text editor.

Build the sample component again:

bazel build --config=fuchsia_x64 //src/hello_world:pkg --publish_to=$HOME/.package_repos/sdk-samples

Run the sample component again (notice the --recreate flag this time):

tools/ffx component run "fuchsia-pkg://fuchsiasamples.com/hello_world#meta/hello_world.cm" --recreate

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
...
[2013.380][core/pkg-resolver][pkg-resolver][I] Fetching blobs for fuchsia-pkg://fuchsiasamples.com/hello_world: []
[2013.380][core/pkg-resolver][pkg-resolver][I] resolved fuchsia-pkg://fuchsiasamples.com/hello_world as fuchsia-pkg://fuchsiasamples.com/hello_world to da1c95e829ec32f78e7b4e8eb845b697679d9cb82432da3cc85763dbc3269395 with TUF
[2013.418][core/ffx-laboratory:hello_world][][I] Hello again, World!

6. 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 the sample component, which generates and registers the debug symbols of the component.
Run the updated sample component.
Verify that the crashed component's logs are in symbolized format.

Do the following:

Use a text editor to edit the src/hello_world/hello_world.cc file, for example:
```
nano src/hello_world/hello_world.cc
```
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";
  abort();
  return 0;
}
```
This update will cause the component to crash immediately after printing a message.
Save the file and exit the text editor.
Rebuild the sample component:
```
bazel build --config=fuchsia_x64 //src/hello_world:pkg --publish_to=$HOME/.package_repos/sdk-samples
```
Building a component automatically generates and registers the component’s debug symbols in your development environment.

Run the updated sample component:

tools/ffx component run "fuchsia-pkg://fuchsiasamples.com/hello_world#meta/hello_world.cm" --recreate

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

tools/ffx log --kernel dump

This command prints output similar to the following:

$ tools/ffx log --kernel dump
...
[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
[174978.450][klog][klog][I]    #1    0x000001d56b552047 in main() src/hello_world/hello_world.cc:9 <<VMO#32996646=blob-a4c56246>>+0x2047 sp 0x11d191bcf80
[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.

7. 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:

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]
```

In the zxdb terminal, attach the debugger to the hello_world.cm component:

[zxdb] attach hello_world.cm

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.

In the zxdb terminal, set a breakpoint at the main() method:

[zxdb] break main

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.

In a different terminal, run the sample component:

tools/ffx component run "fuchsia-pkg://fuchsiasamples.com/hello_world#meta/hello_world.cm" --recreate

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]

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
...
[5538.385][core/pkg-resolver][pkg-resolver][I] Fetching blobs for fuchsia-pkg://fuchsiasamples.com/hello_world: []
[5538.385][core/pkg-resolver][pkg-resolver][I] resolved fuchsia-pkg://fuchsiasamples.com/hello_world as fuchsia-pkg://fuchsiasamples.com/hello_world to 940cbd84428125a90e1fbeba7033af7cb0f857f8f0bb2879d6b07cd1001f2225 with TUF
[5538.408][core/pkg-resolver][pkg-resolver][I] Fetching blobs for fuchsia-pkg://fuchsiasamples.com/hello_world: []
[5538.409][core/pkg-resolver][pkg-resolver][I] resolved fuchsia-pkg://fuchsiasamples.com/hello_world as fuchsia-pkg://fuchsiasamples.com/hello_world to 940cbd84428125a90e1fbeba7033af7cb0f857f8f0bb2879d6b07cd1001f2225 with TUF

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

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

[zxdb] next

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] next
🛑 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:

[5694.479][core/ffx-laboratory:hello_world][][I] Hello again, World!

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.

8. 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.

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:

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>
audio_core.cmx
bootstrap/archivist
bootstrap/driver_manager
bootstrap/fshost
...
core/wlandevicemonitor
core/wlanstack
crash_reports.cmx
feedback_data.cmx
httpsdate_time_source.cmx
scenic.cmx
timekeeper.cmx

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

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.

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 = 531685168169295
  payload:
    root:
      events:
        recent_events:
          319:
            @time = 7730479794
            event = log_sink_requested
            moniker = core/memory_monitor
          320:
            @time = 7782621023
            event = log_sink_requested
            moniker = core/bt-a2dp
          321:
            ...
          516:
            @time = 5538432236492
            event = log_sink_requested
            moniker = core/ffx-laboratory:hello_world
          517:
            @time = 5825449627765
            event = component_stopped
            moniker = debug_agent_channel.cmx:1064825
          518:
            @time = 5825475597828
            event = component_stopped
            moniker = core/ffx-laboratory:hello_world

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

9. Run tests

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

The tasks include:

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

Do the following:

Build the sample test components:

bazel build --config=fuchsia_x64 //src/hello_world:test_pkg --publish_to=$HOME/.package_repos/sdk-samples

When the build is successful, this command prints output similar to the following in the end:

$ bazel build --config=fuchsia_x64 //src/hello_world:test_pkg --publish_to=$HOME/.package_repos/sdk-samples
...
INFO: Elapsed time: 5.027s, Critical Path: 4.53s
INFO: 98 processes: 44 internal, 52 linux-sandbox, 2 local.
INFO: Build completed successfully, 98 total actions

Verify that the basic hello_test passes:

tools/ffx test run "fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_test.cm"

This command prints output similar to the following:

$ tools/ffx test run "fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_test.cm"
Running test 'fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_test.cm'
[RUNNING]       main
[stdout - main]
Example stdout.
[PASSED]        main

1 out of 1 tests passed...
fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_test.cm completed with result: PASSED

Verify that the GoogleTest (gtest) test passes:

tools/ffx test run "fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_gtest.cm"

This command prints output similar to the following:

$ tools/ffx test run "fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_gtest.cm"
Running test 'fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_gtest.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://fuchsiasamples.com/hello_test#meta/hello_gtest.cm completed with result: PASSED

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

Replace EXPECT_STRNE() with EXPECT_STREQ():

The test should look like below:

TEST(HelloTest, BasicAssertions)
{
  // Expect two strings not to be equal.
  EXPECT_STREQ("hello", "world");
  // Expect equality.
  EXPECT_EQ(7 * 6, 42);
}

This change will cause the gtest test to fail.

Save the file and exit the text editor.

Rebuild the sample test components:

bazel build --config=fuchsia_x64 //src/hello_world:test_pkg --publish_to=$HOME/.package_repos/sdk-samples

Verify that the gtest test now fails:

tools/ffx test run "fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_gtest.cm"

This command prints output similar to the following:

$ tools/ffx test run "fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_gtest.cm"
Running test 'fuchsia-pkg://fuchsiasamples.com/hello_test#meta/hello_gtest.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://fuchsiasamples.com/hello_test#meta/hello_gtest.cm completed with result: FAILED
One or more test runs failed.
Tests failed

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

Next steps

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

Appendices

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 fuchsiasamples.com

tools/ffx repository remove workstation.qemu-x64

tools/ffx repository server stop

rm -rf $HOME/.package_repos/sdk-samples

Remove the getting-started directory and its artifacts:

rm -rf $HOME/getting-started

When Bazel fails to build, try the commands below:

bazel clean --expunge

bazel shutdown && rm -rf $HOME/.cache/bazel

Other clean up commands:

killall ffx

killall pm

Update the firewall rules

When you launch the sample component (for instance, using the command tools/ffx component run "fuchsia-pkg://fuchsiasamples.com/hello_world#meta/hello_world.cm"), 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.