Snapcraft fails when snapping .net core console application

[Peter Szucs]

I have a solution with one project called 'console' that simply writes 'Hello World' to the console. After building the application I get an error like this (I included the output from the successful build as well)

Welcome to .NET Core!
---------------------
Learn more about .NET Core @ https://aka.ms/dotnet-docs. Use dotnet --help to see available commands or go to https://aka.ms/dotnet-cli-docs.

Telemetry
--------------
The .NET Core tools collect usage data in order to improve your experience. The data is anonymous and does not include command-line arguments. The data is collected by Microsoft and shared with the community.
You can opt out of telemetry by setting a DOTNET_CLI_TELEMETRY_OPTOUT environment variable to 1 using your favorite shell.
You can read more about .NET Core tools telemetry @ https://aka.ms/dotnet-cli-telemetry.

Configuring...
-------------------
A command is running to initially populate your local package cache, to improve restore speed and enable offline access. This command will take up to a minute to complete and will only happen once.
Decompressing 100% 6489 ms
Expanding 100% 7774 ms
Microsoft (R) Build Engine version 15.5.180.51428 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restoring packages for /root/build_ridersnap/parts/ridersnap/build/console/console.csproj...
  Generating MSBuild file /root/build_ridersnap/parts/ridersnap/build/console/obj/console.csproj.nuget.g.props.
  Generating MSBuild file /root/build_ridersnap/parts/ridersnap/build/console/obj/console.csproj.nuget.g.targets.
  Restore completed in 148.64 ms for /root/build_ridersnap/parts/ridersnap/build/console/console.csproj.
  console -> /root/build_ridersnap/parts/ridersnap/build/console/bin/Release/netcoreapp2.0/console.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:03.07
/root/build_ridersnap/parts/ridersnap/dotnet/sdk/dotnet publish -c Release -o /root/build_ridersnap/parts/ridersnap/install --self-contained -r linux-x64
Microsoft (R) Build Engine version 15.5.180.51428 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restoring packages for /root/build_ridersnap/parts/ridersnap/build/console/console.csproj...
  Installing runtime.linux-x64.Microsoft.NETCore.DotNetAppHost 2.0.0.
  Installing runtime.linux-x64.Microsoft.NETCore.DotNetHostResolver 2.0.0.
  Installing runtime.linux-x64.Microsoft.NETCore.DotNetHostPolicy 2.0.0.
  Installing runtime.linux-x64.Microsoft.NETCore.App 2.0.0.
  Restore completed in 6.99 sec for /root/build_ridersnap/parts/ridersnap/build/console/console.csproj.
  console -> /root/build_ridersnap/parts/ridersnap/build/console/bin/Release/netcoreapp2.0/linux-x64/console.dll
  console -> /root/build_ridersnap/parts/ridersnap/install/
Sorry, an error occurred in Snapcraft:
Traceback (most recent call last):
  File "/usr/bin/snapcraft", line 9, in <module>
    load_entry_point('snapcraft==2.43.1', 'console_scripts', 'snapcraft')()
  File "/usr/lib/python3/dist-packages/click/core.py", line 716, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/click/core.py", line 696, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python3/dist-packages/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3/dist-packages/click/core.py", line 889, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python3/dist-packages/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/snapcraft/cli/lifecycle.py", line 136, in snap
    project = _execute(steps.PRIME, parts=[], **kwargs)
  File "/usr/lib/python3/dist-packages/snapcraft/cli/lifecycle.py", line 35, in _execute
    lifecycle.execute(step, project_config, parts)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 90, in execute
    executor.run(step, part_names)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 194, in run
    self._handle_step(part_names, part, step, current_step, cli_config)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 208, in _handle_step
    getattr(self, "_run_{}".format(current_step.name))(part)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 261, in _run_build
    self._run_step(step=steps.BUILD, part=part, progress="Building")
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 327, in _run_step
    getattr(part, step.name)()
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/__init__.py", line 523, in build
    self._do_build()
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/__init__.py", line 545, in _do_build
    self._runner.build()
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/_runner.py", line 97, in build
    "override-build", self._override_build_scriptlet, self._builddir
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/_runner.py", line 162, in _run_scriptlet
    scriptlet_name, function_call.strip()
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/_runner.py", line 218, in _handle_builtin_function
    function(**function_args)
  File "/usr/lib/python3/dist-packages/snapcraft/plugins/dotnet.py", line 175, in build
    appname = os.path.join(self.installdir, self._get_appname())
  File "/usr/lib/python3.5/posixpath.py", line 89, in join
    genericpath._check_arg_types('join', a, *p)
  File "/usr/lib/python3.5/genericpath.py", line 143, in _check_arg_types
    (funcname, s.__class__.__name__)) from None
TypeError: join() argument must be str or bytes, not 'NoneType'
We would appreciate it if you created a bug report at
https://launchpad.net/snapcraft/+filebug with the above text included.
Stopping local:snapcraft-weekly-first-cod

----
Contents of my snapcraft.yaml:

name: ridersnap
version: '0.1'
summary: Woo
description: Hoo
grade: devel
confinement: devmode

parts:
  ridersnap:
    plugin:
      dotnet

apps:
  ridersnap:
    command: ridersnap

----
Project structure:
ridersnap (solution folder)
  ridersnap.sln
  snapcraft.yaml
  console (project folder)
    console.csproj
    Program.cs

[Sergio Schvezov (sergiusens)]

https://github.com/snapcore/snapcraft/pull/2534

[Sergio Schvezov (sergiusens)]

discard comment #1, wrong bug

[Sergio Schvezov (sergiusens)]

Mind trying with my slightly modified yaml to trigger snapcraft 3.0 behavior? (setting a base) and using the snapcraft snap instead?

sergiusens@gotham:~/projects$ dotnet new console -n ridersnap
The template "Console Application" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on ridersnap/ridersnap.csproj...
  Restore completed in 145,06 ms for /home/sergiusens/projects/ridersnap/ridersnap.csproj.

Restore succeeded.

sergiusens@gotham:~/projects$ cd ridersnap/
# Changed the target in ridersnap.csproj to 2.0 considering that is what the plugin supports.
sergiusens@gotham:~/projects/ridersnap$ cat > .snapcraft.yaml <<EOF
> name: ridersnap
> base: core
> version: '0.1'
> summary: Woo
> description: Hoo
> grade: devel
> confinement: devmode
>
> parts:
> ridersnap:
> source: .
> plugin: dotnet
>
> apps:
> ridersnap:
> command: ridersnap
> EOF
sergiusens@gotham:~/projects/ridersnap$ snap list snapcraft
Name Version Rev Tracking Publisher Notes
snapcraft 3.4 2832 candidate canonical✓ classic

Then,
sergiusens@gotham:~/projects/ridersnap$ snapcraft --use-lxd
Using '.snapcraft.yaml': Project assets will be searched for from the 'snap' directory.
The LXD provider is offered as a technology preview for early adopters.
The command line interface, container names or lifecycle handling may change in upcoming releases.
Launching a container.
/snap/snapcraft/2832/lib/python3.5/site-packages/pylxd/models/operation.py:59: UserWarning: Attempted to set unknown attribute "location" on instance of "Operation"
  .format(key, self.__class__.__name__))
Waiting for cloud-init
...
status: done
error: no changes of type "auto-refresh" found
snap "core" has no updates available
snap "snapcraft" has no updates available
snap "core" has no updates available
Using '.snapcraft.yaml': Project assets will be searched for from the 'snap' directory.
Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [109 kB]
Hit http://archive.ubuntu.com/ubuntu xenial InRelease
Get:2 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
Get:3 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]
Fetched 325 kB in 0s (0 B/s)
Updating pull step for ridersnap (source changed)
Building ridersnap
/root/parts/ridersnap/dotnet/sdk/dotnet build -c Release
Microsoft (R) Build Engine version 15.5.180.51428 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restoring packages for /root/parts/ridersnap/build/ridersnap.csproj...
  Generating MSBuild file /root/parts/ridersnap/build/obj/ridersnap.csproj.nuget.g.props.
  Generating MSBuild file /root/parts/ridersnap/build/obj/ridersnap.csproj.nuget.g.targets.
  Restore completed in 127.28 ms for /root/parts/ridersnap/build/ridersnap.csproj.
  ridersnap -> /root/parts/ridersnap/build/bin/Release/netcoreapp2.0/ridersnap.dll

Build succeeded.
  ...

[Sergio Schvezov (sergiusens)]

At the time of this writing, --use-lxd is only available on snapcraft 3.4, currently in the candidate channel. You can omit the --use-lxd if you want snapcraft from the stable channel which default to the a different underlying build tech.

[trampster (trampster)]

I also am having this issue. Is there any work around or do I need to use the dump plugin instead?

Here is my yaml

name: ropuclient
base: core # core18 isnt supported
version: '0.1' # just for humans, typically '1.2+git' or '1.3.2'
summary: Ropu PTT client # 79 char long summary
description: |
  PTT (Push to Talk) client for the Ropu group PTT system

grade: devel # must be 'stable' to release into candidate/stable channels
confinement: devmode # use 'strict' once you have the right plugs and slots

parts:
  ropuclient:
    # See 'snapcraft plugins'
    source: .
    plugin: dotnet
    dotnet-runtime-version: 2.1.9 #defaults to dotnet 2.0

[trampster (trampster)]

My code is available here: https://github.com/trampster/Ropu if you want to reproduce this exactly

[trampster (trampster)]

My solutions is multiproject, that is there are two dotnet projects with a solution (.sln) file that ties them together.

This works with the dotnet tool but means that when you do dotnet publish -o InstallDir

The InstallDir will be a subdirectly of the project not at the root, I am guessing that this may be what is causing the dotnet plugin to crash.

[mase (i-lp-f)]

This works in 18.04

Fetched 176 kB in 0s (0 B/s)
Pulling ropu
Skipping build desktop-gnome-platform (already ran)
Building ropu
Skipping stage desktop-gnome-platform (already ran)
Staging ropu
Priming desktop-gnome-platform
Priming ropu
Files from the build host were migrated into the snap to satisfy dependencies that would otherwise not be met. This feature will be removed in a future release. If these libraries are needed in the final snap, ensure that the following are either satisfied by a stage-packages entry or through a part:
usr/lib/x86_64-linux-gnu/liblttng-ust-tracepoint.so.0
usr/lib/x86_64-linux-gnu/liblttng-ust.so.0
usr/lib/x86_64-linux-gnu/liburcu-bp.so.6
usr/lib/x86_64-linux-gnu/liburcu-cds.so.6
Snapping 'ropu' |
Snapped ropu_0.1_amd64.snap

[Sergio Schvezov (sergiusens)]

This bug has been marked as Invalid as it cannot be reproduced with the detail provided.
If this issue is still occurring feel free to open a new bug or re-open this one with enough detail (host OS, versions of software used, ...) to be able to reproduce.

[trampster (trampster)]

Sorry you didn't reproduce it, because I already switched to using the dump plugin because the dotnet one didn't work. I am using ubuntu 18.04

[trampster (trampster)]

I had given up waiting