ROS2 with snaps tutorial

snapcraft
1

I’m following the ROS2 snaps document here for Core 22 on my 22.04 LTS host. The build step produces the following error. Does anyone have any idea where to look for a solution?

$ SNAPCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS=1 snapcraft
*EXPERIMENTAL* extension 'ros2-humble' enabled                                        
Launching instance...                                                                 Traceback (most recent call last):
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/bases/buildd.py", line 798, in _setup_snapd_proxy
executor.execute_run(command, capture_output=True, check=True)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/lxd/lxd_instance.py", line 289, in execute_run
return self.lxc.exec(
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/lxd/lxc.py", line 329, in exec
return runner(final_cmd, **kwargs)  # pylint: disable=subprocess-run-check
  File "/snap/snapcraft/8528/usr/lib/python3.8/subprocess.py", line 516, in run
raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['lxc', '--project', 'snapcraft', 'exec', 'local:snapcraft-ros2-talker-listener-on-amd64-for-amd64-5643208', '--', 'env', 'PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin', 'SNAPCRAFT_MANAGED_MODE=1', 'SNAPCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS=1', 'snap', 'unset', 'system', 'proxy.http']' returned non-zero exit status 127.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/lxd/lxd_provider.py", line 126, in launched_environment
instance = launch(
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/lxd/launcher.py", line 176, in launch
base_configuration.warmup(executor=instance)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/bases/buildd.py", line 394, in warmup
self._setup_snapd_proxy(executor=executor, deadline=deadline)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/bases/buildd.py", line 809, in _setup_snapd_proxy
raise BaseConfigurationError(
craft_providers.bases.errors.BaseConfigurationError: Failed to set the snapd proxy.
* Command that failed: 'lxc --project snapcraft exec local:snapcraft-ros2-talker-listener-on-amd64-for-amd64-5643208 -- env PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin SNAPCRAFT_MANAGED_MODE=1 SNAPCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS=1 snap unset system proxy.http'
* Command exit code: 127
* Command standard error output: b'env: \xe2\x80\x98snap\xe2\x80\x99: No such file or directory\nError: Command not found\n'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/snap/snapcraft/8528/bin/snapcraft", line 8, in <module>
sys.exit(run())
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/snapcraft/cli.py", line 228, in run
_run_dispatcher(dispatcher)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/snapcraft/cli.py", line 204, in _run_dispatcher
dispatcher.run()
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_cli/dispatcher.py", line 448, in run
return self._loaded_command.run(self._parsed_command_args)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/snapcraft/commands/lifecycle.py", line 259, in run
super().run(parsed_args)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/snapcraft/commands/lifecycle.py", line 132, in run
parts_lifecycle.run(self.name, parsed_args)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/snapcraft/parts/lifecycle.py", line 208, in run
_run_command(
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/snapcraft/parts/lifecycle.py", line 249, in _run_command
_run_in_provider(project, command_name, parsed_args)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/snapcraft/parts/lifecycle.py", line 531, in _run_in_provider
with provider.launched_environment(
  File "/snap/snapcraft/8528/usr/lib/python3.8/contextlib.py", line 113, in __enter__
return next(self.gen)
  File "/snap/snapcraft/8528/lib/python3.8/site-packages/craft_providers/lxd/lxd_provider.py", line 140, in launched_environment
raise LXDError(str(error)) from error
craft_providers.lxd.errors.LXDError: Failed to set the snapd proxy.
* Command that failed: 'lxc --project snapcraft exec local:snapcraft-ros2-talker-listener-on-amd64-for-amd64-5643208 -- env PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin SNAPCRAFT_MANAGED_MODE=1 SNAPCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS=1 snap unset system proxy.http'
* Command exit code: 127
* Command standard error output: b'env: \xe2\x80\x98snap\xe2\x80\x99: No such file or directory\nError: Command not found\n'
2

Is lxd correctly installed and configured on your system? Return code 127 suggests that it’s not available, what does lxc list return?

2 Likes
3

Hello Claudio,

Thanks for your response. Here is what I had for lxc list:

$ lxc list
+------+-------+------+------+------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+------+-------+------+------+------+-----------+
$ sudo snap install lxd
[sudo] password for rasid: 
snap "lxd" is already installed, see 'snap help refresh'
$ sudo lxd init --auto
$ lxc list
+------+-------+------+------+------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+------+-------+------+------+------+-----------+

I was still getting the same error. Then, I removed lxd and reinstalled it:

$ sudo snap remove lxd
2022-11-12T09:38:18-08:00 INFO Waiting for "snap.lxd.daemon.service" to stop.
lxd removed
$ sudo snap install lxd
lxd 5.7-c62733b from Canonical✓ installed
$ sudo lxd init --auto

Then, the build worked :exploding_head:

$ SNAPCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS=1 snapcraft
*EXPERIMENTAL* extension 'ros2-humble' enabled                                                                                 
Launching instance...                                                                                                          
*EXPERIMENTAL* extension 'ros2-humble' enabled                                                                                 
Installed package repositories                                                                                                 
Executed: pull ros-demos                                                                                                       
Executed: pull ros2-humble/ros2-launch                                                                                         
Executed: overlay ros-demos                                                                                                    
Executed: overlay ros2-humble/ros2-launch                                                                                      
Executed: build ros-demos                                                                                                      
Executed: build ros2-humble/ros2-launch                                                                                        
Executed: stage ros-demos                                                                                                      
Executed: stage ros2-humble/ros2-launch                                                                                        
Executed: prime ros-demos                                                                                                      
Executed: prime ros2-humble/ros2-launch                                                                                        
Executed parts lifecycle                                                                                                       
Generated snap metadata                                                                                                        
Unable to determine library dependencies for 'opt/ros/humble/local/lib/python3.10/dist-packages/action_msgs/libaction_msgs__rosidl_generator_py.so'                                                                                                            
Created snap package ros2-talker-listener_0.1_amd64.snap

Moving onto the next issue (to be discovered :wink:)

1 Like