Remote build fails on dangling symlinks

[bepri]

Bug Description

Attempting to use remote-build while in a directory that has dangling symlinks fails. This failure mode should not be forced by the craft tool, but rather should become a failure by the consuming build tools that the craft tool invokes (if it even is an error).

To Reproduce

Create a broken symlink in any project, commit it, and then attempt to run remote-build.

For example,

├── here -> to-here  # `to-here` doesn't exist!
└── snap
    └── snapcraft.yaml

part yaml

Irrelevant

Relevant log output

2026-06-25 11:18:42.312 Starting snapcraft, version 9.0.0
2026-06-25 11:18:42.312 Log verbosity level set to BRIEF
2026-06-25 11:18:42.312 Setting up Project
2026-06-25 11:18:42.312 Project file found at '/home/imani/work/scratch/snap/snapcraft.yaml'
2026-06-25 11:18:42.312 Loading project file 'snap/snapcraft.yaml
2026-06-25 11:18:42.313 Setting up BuildPlan
2026-06-25 11:18:42.313 Build plan contains 1 build(s).
2026-06-25 11:18:42.315 Loading app plugin sdplug
2026-06-25 11:18:42.338 Forward environment variables
2026-06-25 11:18:42.338 Registering craft-sd source handlers
2026-06-25 11:18:42.338 Registering craft-sd services
2026-06-25 11:18:42.338 SD not enabled. Skipping adding commands
2026-06-25 11:18:42.338 Request craft-sd snap installation in managed instance
2026-06-25 11:18:42.338 Skipping store secrets callback registration: SD not enabled.
2026-06-25 11:18:42.338 Preparing application...
2026-06-25 11:18:42.338 Setting up ConfigService
2026-06-25 11:18:42.342 Merging commands for group 'Lifecycle':
2026-06-25 11:18:42.342   - using application command for 'clean'.
2026-06-25 11:18:42.342   - using application command for 'pull'.
2026-06-25 11:18:42.342   - using application command for 'build'.
2026-06-25 11:18:42.342   - using application command for 'stage'.
2026-06-25 11:18:42.342   - using application command for 'prime'.
2026-06-25 11:18:42.342   - using application command for 'pack'.
2026-06-25 11:18:42.342 Merging commands for group 'Other':
2026-06-25 11:18:42.342 Configuring application...
2026-06-25 11:18:42.346 Build plan: platform=None, build_for=None
2026-06-25 11:18:42.346 Running snapcraft remote-build on host
2026-06-25 11:18:42.346 remote-build is experimental and is subject to change. Use with caution.
2026-06-25 11:18:42.346 Setting up RequestService
2026-06-25 11:18:42.346 Logging in with credentials file /home/imani/.local/share/snapcraft/launchpad-credentials.
2026-06-25 11:18:42.346 Emitter: Pausing control of the terminal
2026-06-25 11:18:47.629 Emitter: Resuming control of the terminal
2026-06-25 11:18:47.629 Trying to get project scratch (attempt 1/6)
2026-06-25 11:18:47.936 Emitter: Pausing control of the terminal
2026-06-25 11:18:48.750 Emitter: Resuming control of the terminal
2026-06-25 11:18:48.750 Build plan contains 1 build(s).
2026-06-25 11:18:48.750 Using '--build-for' as the list of architectures to build for
2026-06-25 11:18:48.750 Architectures to build for: 'amd64'
2026-06-25 11:18:48.750 Created project variables {'version': {'value': '0.1', 'updated': False, 'part-name': None}, 'grade': {'value': 'devel', 'updated': False, 'part-name': None}}.
2026-06-25 11:18:48.751 Using parallel build count of 16 from CPU count
2026-06-25 11:18:48.751 Checking if 'version' exists.
2026-06-25 11:18:48.751 Getting value for 'version'.
2026-06-25 11:18:48.751 Got '0.1' (updated=False) for 'version'.
2026-06-25 11:18:48.751 'version' exists.
2026-06-25 11:18:48.751 Getting value for 'version'.
2026-06-25 11:18:48.751 Got '0.1' (updated=False) for 'version'.
2026-06-25 11:18:48.751 Checking if 'version' exists.
2026-06-25 11:18:48.751 Getting value for 'version'.
2026-06-25 11:18:48.751 Got '0.1' (updated=False) for 'version'.
2026-06-25 11:18:48.751 'version' exists.
2026-06-25 11:18:48.751 Getting value for 'version'.
2026-06-25 11:18:48.751 Got '0.1' (updated=False) for 'version'.
2026-06-25 11:18:48.751 Checking if 'grade' exists.
2026-06-25 11:18:48.751 Getting value for 'grade'.
2026-06-25 11:18:48.751 Got 'devel' (updated=False) for 'grade'.
2026-06-25 11:18:48.751 'grade' exists.
2026-06-25 11:18:48.751 Getting value for 'grade'.
2026-06-25 11:18:48.751 Got 'devel' (updated=False) for 'grade'.
2026-06-25 11:18:48.751 Processing grammar (on amd64 for amd64)
2026-06-25 11:18:48.751 Processing grammar for plugin: nil
2026-06-25 11:18:48.757 Starting new build. It may take a while to upload large projects.
2026-06-25 11:18:48.759 snapcraft internal error: Error([('/home/imani/work/scratch/here', '/home/imani/.cache/snapcraft/remote-build/snapcraft-scratch-a22566aae87cb46312173f84fc845a49/repo/here', "[Errno 2] No such file or directory: '/home/imani/work/scratch/here'")])
2026-06-25 11:18:48.771 Traceback (most recent call last):
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_application/application.py", line 693, in run
2026-06-25 11:18:48.771     return_code = self._run_inner()
2026-06-25 11:18:48.771                   ^^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/snapcraft/application.py", line 180, in _run_inner
2026-06-25 11:18:48.771     return_code = super()._run_inner()
2026-06-25 11:18:48.771                   ^^^^^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_application/application.py", line 670, in _run_inner
2026-06-25 11:18:48.771     return_code = dispatcher.run() or os.EX_OK
2026-06-25 11:18:48.771                   ^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_cli/dispatcher.py", line 576, in run
2026-06-25 11:18:48.771     return self._loaded_command.run(self._parsed_command_args)
2026-06-25 11:18:48.771            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_application/commands/base.py", line 222, in run
2026-06-25 11:18:48.771     result = self._run(parsed_args, **kwargs) or result
2026-06-25 11:18:48.771              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_application/commands/remote.py", line 162, in _run
2026-06-25 11:18:48.771     builds = builder.start_builds(project_dir, **build_args)
2026-06-25 11:18:48.771              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_application/services/remotebuild.py", line 133, in start_builds
2026-06-25 11:18:48.771     _, self._repository = self._ensure_repository(project_dir)
2026-06-25 11:18:48.771                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_application/services/remotebuild.py", line 278, in _ensure_repository
2026-06-25 11:18:48.771     work_tree.init_repo()
2026-06-25 11:18:48.771   File "/snap/snapcraft/18124/lib/python3.12/site-packages/craft_application/remote/worktree.py", line 54, in init_repo
2026-06-25 11:18:48.771     copytree(self._project_dir, self._repo_dir)
2026-06-25 11:18:48.771   File "/snap/snapcraft/current/usr/lib/python3.12/shutil.py", line 600, in copytree
2026-06-25 11:18:48.771     return _copytree(entries=entries, src=src, dst=dst, symlinks=symlinks,
2026-06-25 11:18:48.771            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-06-25 11:18:48.771   File "/snap/snapcraft/current/usr/lib/python3.12/shutil.py", line 554, in _copytree
2026-06-25 11:18:48.771     raise Error(errors)
2026-06-25 11:18:48.771 shutil.Error: [('/home/imani/work/scratch/here', '/home/imani/.cache/snapcraft/remote-build/snapcraft-scratch-a22566aae87cb46312173f84fc845a49/repo/here', "[Errno 2] No such file or directory: '/home/imani/work/scratch/here'")]
2026-06-25 11:18:48.771 Full execution log: '/home/imani/.local/state/snapcraft/log/snapcraft-20260625-111842.312392.log'