[Bug] Devcontainer setup is broken

[kaladron]

Brief Issue Summary

When working to patch a bug here, I created a Codespace to work on it. The Devcontainer config is not working because of this error:

The following error occurred reading the devcontainer.json file - "After parsing a value an unexpected character was encountered: [. Path 'extensions', line 12, position 24."

CMake Tools Diagnostics

n/a

Debug Log

Here's the creation log from the codespace:


=================================================================================
2025-10-09 07:45:44.163Z: Configuration starting...
2025-10-09 07:45:44.173Z: Cloning...

====================================== ERROR ====================================
2025-10-09 07:45:44.183Z: The following error occurred reading the devcontainer.json file - "After parsing a value an unexpected character was encountered: [. Path 'extensions', line 12, position 24." Please see https://docs.github.com/en/enterprise-cloud@latest/codespaces/setting-up-your-project-for-codespaces/introduction-to-dev-containers#devcontainerjson for help configuring your file.
=================================================================================

====================================== ERROR ====================================
2025-10-09 07:45:44.187Z: Container creation failed.
=================================================================================
2025-10-09 07:45:44.193Z: 

===================================== WARNING ===================================
2025-10-09 07:45:44.194Z: Creating recovery container.
=================================================================================

=================================================================================
2025-10-09 07:45:45.338Z: Creating container...
2025-10-09 07:45:45.376Z: $ devcontainer up --id-label Type=codespaces --workspace-folder /var/lib/docker/codespacemount/workspace/vscode-cmake-tools --mount type=bind,source=/.codespaces/agent/mount/cache,target=/vscode --user-data-folder /var/lib/docker/codespacemount/.persistedshare --container-data-folder .vscode-remote/data/Machine --container-system-data-folder /var/vscode-remote --log-level trace --log-format json --update-remote-user-uid-default never --mount-workspace-git-root false --omit-config-remote-env-from-metadata --skip-non-blocking-commands --skip-post-create --config "/var/lib/docker/codespacemount/workspace/vscode-cmake-tools/.devcontainer/devcontainer.json" --override-config /root/.codespaces/shared/merged_devcontainer.json --default-user-env-probe loginInteractiveShell --container-session-data-folder /workspaces/.codespaces/.persistedshare/devcontainers-cli/cache --secrets-file /root/.codespaces/shared/user-secrets-envs.json
2025-10-09 07:45:45.511Z: @devcontainers/cli 0.80.0. Node.js v18.20.6. linux 6.8.0-1030-azure x64.
2025-10-09 07:45:46.026Z: $alpine -c echo Container started
2025-10-09 07:45:46.048Z: Unable to find image 'mcr.microsoft.com/devcontainers/base:alpine' locally
2025-10-09 07:45:46.187Z: alpine: Pulling from devcontainers/base
2025-10-09 07:45:46.228Z: 
�[1A�[2K
9824c27679d3: Pulling fs layer 
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64460e5168e0: Pulling fs layer 
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44c75e786264: Pulling fs layer 
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a63fa575778c: Pulling fs layer 
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85553cdd1418: Pulling fs layer 
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2025-10-09 07:45:46.229Z: ba79d01ae1c8: Pulling fs layer 
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7add29b687fa: Pulling fs layer 
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85553cdd1418: Waiting 
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ba79d01ae1c8: Waiting 
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7add29b687fa: Waiting 
�[1B�[4A2025-10-09 07:45:46.230Z: �[2K
a63fa575778c: Waiting 
�[4B2025-10-09 07:45:46.307Z: �[7A2025-10-09 07:45:46.307Z: �[2K
9824c27679d3: Downloading  48.34kB/3.8MB
�[7B2025-10-09 07:45:46.316Z: �[6A�[2K
64460e5168e0: Downloading     408B/408B
�[6B�[6A�[2K
64460e5168e0: Verifying Checksum 
�[6B�[6A�[2K
64460e5168e0: Download complete 
�[6B2025-10-09 07:45:46.329Z: �[5A�[2K
44c75e786264: Downloading     135B/135B
�[5B2025-10-09 07:45:46.330Z: �[5A�[2K
44c75e786264: Verifying Checksum 
�[5B�[5A�[2K
44c75e786264: Download complete 
�[5B2025-10-09 07:45:46.332Z: �[7A�[2K
9824c27679d3: Verifying Checksum 
�[7B�[7A�[2K
2025-10-09 07:45:46.333Z: 9824c27679d3: Download complete 
�[7B2025-10-09 07:45:46.337Z: �[7A�[2K
9824c27679d3: Extracting  65.54kB/3.8MB
�[7B2025-10-09 07:45:46.453Z: �[2A�[2K
ba79d01ae1c8: Downloading  538.7kB/206.1MB
�[2B2025-10-09 07:45:46.457Z: �[3A2025-10-09 07:45:46.457Z: �[2K
85553cdd1418: Downloading     233B/233B
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85553cdd1418: Verifying Checksum 
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85553cdd1418: Download complete 
�[3B2025-10-09 07:45:46.477Z: �[7A2025-10-09 07:45:46.477Z: �[2K
9824c27679d3: Extracting  262.1kB/3.8MB
�[7B2025-10-09 07:45:46.565Z: �[2A�[2K2025-10-09 07:45:46.566Z: 
ba79d01ae1c8: Downloading  26.48MB/206.1MB
�[2B2025-10-09 07:45:46.572Z: �[1A2025-10-09 07:45:46.572Z: �[2K
7add29b687fa: Downloading  440.4kB/42.49MB
�[1B2025-10-09 07:45:46.578Z: �[7A�[2K2025-10-09 07:45:46.578Z: 
9824c27679d3: Extracting  2.163MB/3.8MB
�[7B2025-10-09 07:45:46.644Z: �[7A�[2K
9824c27679d3: Extracting    3.8MB/3.8MB
�[7B2025-10-09 07:45:46.656Z: �[2A�[2K
ba79d01ae1c8: Downloading  52.97MB/206.1MB
�[2B2025-10-09 07:45:46.680Z: �[7A2025-10-09 07:45:46.681Z: �[2K
9824c27679d3: Pull complete 
�[7B2025-10-09 07:45:46.683Z: �[1A�[2K
7add29b687fa: Downloading  23.45MB/42.49MB
�[1B2025-10-09 07:45:46.688Z: �[4A�[2K2025-10-09 07:45:46.688Z: 
a63fa575778c: Downloading     223B/223B
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a63fa575778c: Verifying Checksum 
�[4B�[4A2025-10-09 07:45:46.689Z: �[2K
a63fa575778c: Download complete 
�[4B2025-10-09 07:45:46.693Z: �[6A�[2K
64460e5168e0: 2025-10-09 07:45:46.694Z: Extracting     408B/408B
�[6B�[6A�[2K
64460e5168e0: Extracting     408B/408B
�[6B2025-10-09 07:45:46.762Z: �[2A�[2K
ba79d01ae1c8: Downloading  69.19MB/206.1MB
�[2B2025-10-09 07:45:46.787Z: �[1A�[2K
7add29b687fa: Downloading  40.48MB/42.49MB
�[1B2025-10-09 07:45:46.810Z: �[1A�[2K2025-10-09 07:45:46.810Z: 
7add29b687fa: Verifying Checksum 
�[1B�[1A�[2K
7add29b687fa: Download complete 
�[1B2025-10-09 07:45:46.859Z: �[2A�[2K
ba79d01ae1c8: Downloading  83.79MB/206.1MB
�[2B2025-10-09 07:45:46.959Z: �[2A�[2K2025-10-09 07:45:46.959Z: 
ba79d01ae1c8: Downloading  112.4MB/206.1MB
�[2B2025-10-09 07:45:47.064Z: �[2A�[2K
ba79d01ae1c8: Downloading  139.5MB/206.1MB
�[2B2025-10-09 07:45:47.166Z: �[2A�[2K2025-10-09 07:45:47.166Z: 
ba79d01ae1c8: Downloading  155.2MB/206.1MB
�[2B2025-10-09 07:45:47.265Z: �[2A2025-10-09 07:45:47.266Z: �[2K
ba79d01ae1c8: Downloading  178.9MB/206.1MB
�[2B2025-10-09 07:45:47.366Z: �[2A�[2K
ba79d01ae1c8: Downloading  204.9MB/206.1MB
�[2B2025-10-09 07:45:47.373Z: �[2A�[2K2025-10-09 07:45:47.374Z: 
ba79d01ae1c8: Verifying Checksum 
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ba79d01ae1c8: Download complete 
�[2B2025-10-09 07:45:47.782Z: �[6A�[2K
64460e5168e0: Pull complete 
�[6B2025-10-09 07:45:47.786Z: �[5A2025-10-09 07:45:47.786Z: �[2K
44c75e786264: Extracting     135B/135B
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44c75e786264: Extracting     135B/135B
�[5B2025-10-09 07:45:48.691Z: �[5A�[2K
44c75e786264: Pull complete 
�[5B2025-10-09 07:45:48.694Z: �[4A�[2K
a63fa575778c: Extracting     223B/223B
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a63fa575778c: Extracting     223B/223B
�[4B2025-10-09 07:45:48.707Z: �[4A�[2K
2025-10-09 07:45:48.708Z: a63fa575778c: Pull complete 
�[4B2025-10-09 07:45:48.711Z: �[3A2025-10-09 07:45:48.711Z: �[2K
85553cdd1418: Extracting     233B/233B
�[3B2025-10-09 07:45:48.712Z: �[3A2025-10-09 07:45:48.713Z: �[2K
85553cdd1418: Extracting     233B/233B
�[3B2025-10-09 07:45:48.724Z: �[3A�[2K
85553cdd1418: Pull complete 
�[3B2025-10-09 07:45:48.737Z: �[2A�[2K
ba79d01ae1c8: Extracting  557.1kB/206.1MB
�[2B2025-10-09 07:45:48.839Z: �[2A�[2K
ba79d01ae1c8: Extracting  6.128MB/206.1MB
�[2B2025-10-09 07:45:48.943Z: �[2A�[2K
ba79d01ae1c8: Extracting  13.93MB/206.1MB
�[2B2025-10-09 07:45:49.051Z: �[2A2025-10-09 07:45:49.052Z: �[2K
ba79d01ae1c8: Extracting  21.17MB/206.1MB
�[2B2025-10-09 07:45:49.163Z: �[2A�[2K
ba79d01ae1c8: Extracting  24.51MB/206.1MB
�[2B2025-10-09 07:45:49.276Z: �[2A�[2K
ba79d01ae1c8: Extracting  25.62MB/206.1MB
�[2B2025-10-09 07:45:49.380Z: �[2A�[2K
2025-10-09 07:45:49.381Z: ba79d01ae1c8: Extracting  26.74MB/206.1MB
�[2B2025-10-09 07:45:49.490Z: �[2A�[2K
ba79d01ae1c8: Extracting  30.08MB/206.1MB
�[2B2025-10-09 07:45:49.596Z: �[2A�[2K
ba79d01ae1c8: Extracting  32.31MB/206.1MB
2025-10-09 07:45:49.596Z: �[2B2025-10-09 07:45:49.701Z: �[2A�[2K
ba79d01ae1c8: Extracting  41.22MB/206.1MB
�[2B2025-10-09 07:45:49.805Z: �[2A�[2K
ba79d01ae1c8: Extracting  48.46MB/206.1MB
�[2B2025-10-09 07:45:49.905Z: �[2A�[2K
ba79d01ae1c8: Extracting  54.59MB/206.1MB
�[2B2025-10-09 07:45:50.018Z: �[2A�[2K
ba79d01ae1c8: Extracting  57.93MB/206.1MB
�[2B2025-10-09 07:45:50.128Z: �[2A2025-10-09 07:45:50.129Z: �[2K
ba79d01ae1c8: Extracting  62.95MB/206.1MB
�[2B2025-10-09 07:45:50.232Z: �[2A�[2K
ba79d01ae1c8: Extracting  70.19MB/206.1MB
�[2B2025-10-09 07:45:50.333Z: �[2A�[2K
ba79d01ae1c8: Extracting  79.66MB/206.1MB
2025-10-09 07:45:50.334Z: �[2B2025-10-09 07:45:50.452Z: �[2A2025-10-09 07:45:50.453Z: �[2K
ba79d01ae1c8: Extracting  84.12MB/206.1MB
�[2B2025-10-09 07:45:50.567Z: �[2A2025-10-09 07:45:50.568Z: �[2K
ba79d01ae1c8: Extracting  87.46MB/206.1MB
�[2B2025-10-09 07:45:50.679Z: �[2A�[2K
2025-10-09 07:45:50.679Z: ba79d01ae1c8: Extracting  89.69MB/206.1MB
�[2B2025-10-09 07:45:50.783Z: �[2A�[2K
ba79d01ae1c8: 2025-10-09 07:45:50.784Z: Extracting  98.04MB/206.1MB
�[2B2025-10-09 07:45:50.887Z: �[2A2025-10-09 07:45:50.888Z: �[2K
ba79d01ae1c8: Extracting  105.3MB/206.1MB
�[2B2025-10-09 07:45:50.993Z: �[2A2025-10-09 07:45:50.994Z: �[2K
ba79d01ae1c8: Extracting  114.2MB/206.1MB
�[2B2025-10-09 07:45:51.099Z: �[2A�[2K2025-10-09 07:45:51.100Z: 
ba79d01ae1c8: Extracting  121.4MB/206.1MB
�[2B2025-10-09 07:45:51.204Z: �[2A�[2K
ba79d01ae1c8: Extracting  130.4MB/206.1MB
�[2B2025-10-09 07:45:51.330Z: �[2A�[2K
ba79d01ae1c8: Extracting  137.6MB/206.1MB
�[2B2025-10-09 07:45:51.434Z: �[2A�[2K
2025-10-09 07:45:51.436Z: ba79d01ae1c8: Extracting  139.8MB/206.1MB
�[2B2025-10-09 07:45:51.549Z: �[2A�[2K
ba79d01ae1c8: Extracting  143.7MB/206.1MB
�[2B2025-10-09 07:45:51.657Z: �[2A�[2K
ba79d01ae1c8: Extracting  148.7MB/206.1MB
�[2B2025-10-09 07:45:51.769Z: �[2A�[2K
ba79d01ae1c8: Extracting  153.2MB/206.1MB
�[2B2025-10-09 07:45:52.834Z: �[2A�[2K
ba79d01ae1c8: Extracting  157.1MB/206.1MB
�[2B2025-10-09 07:45:52.936Z: �[2A2025-10-09 07:45:52.936Z: �[2K
ba79d01ae1c8: Extracting  164.9MB/206.1MB
�[2B2025-10-09 07:45:53.038Z: �[2A�[2K
2025-10-09 07:45:53.039Z: ba79d01ae1c8: Extracting  173.2MB/206.1MB
�[2B2025-10-09 07:45:53.145Z: �[2A2025-10-09 07:45:53.146Z: �[2K
ba79d01ae1c8: Extracting  182.2MB/206.1MB
�[2B2025-10-09 07:45:53.246Z: �[2A2025-10-09 07:45:53.246Z: �[2K
ba79d01ae1c8: Extracting    190MB/206.1MB
�[2B2025-10-09 07:45:53.392Z: �[2A�[2K
ba79d01ae1c8: Extracting  195.5MB/206.1MB
�[2B2025-10-09 07:45:53.520Z: �[2A�[2K
ba79d01ae1c8: Extracting  197.8MB/206.1MB
�[2B2025-10-09 07:45:53.624Z: �[2A�[2K
ba79d01ae1c8: Extracting  199.4MB/206.1MB
�[2B2025-10-09 07:45:53.736Z: �[2A�[2K
ba79d01ae1c8: Extracting  200.5MB/206.1MB
�[2B2025-10-09 07:45:53.925Z: �[2A�[2K2025-10-09 07:45:53.926Z: 
ba79d01ae1c8: Extracting  201.7MB/206.1MB
�[2B2025-10-09 07:45:54.139Z: �[2A�[2K
ba79d01ae1c8: Extracting  203.3MB/206.1MB
�[2B2025-10-09 07:45:54.291Z: �[2A�[2K
ba79d01ae1c8: Extracting  203.9MB/206.1MB
�[2B2025-10-09 07:45:54.302Z: �[2A2025-10-09 07:45:54.307Z: �[2K
2025-10-09 07:45:54.307Z: ba79d01ae1c8: Extracting  206.1MB/206.1MB
2025-10-09 07:45:54.307Z: �[2B2025-10-09 07:45:57.249Z: �[2A�[2K
ba79d01ae1c8: Pull complete 
�[2B2025-10-09 07:45:57.263Z: �[1A2025-10-09 07:45:57.264Z: �[2K
7add29b687fa: Extracting    426kB/42.49MB
�[1B2025-10-09 07:45:57.368Z: �[1A�[2K
7add29b687fa: Extracting  1.704MB/42.49MB
�[1B2025-10-09 07:45:57.557Z: �[1A�[2K
7add29b687fa: Extracting  5.964MB/42.49MB
�[1B2025-10-09 07:45:57.713Z: �[1A�[2K
7add29b687fa: Extracting  12.78MB/42.49MB
�[1B2025-10-09 07:45:57.814Z: �[1A�[2K
7add29b687fa: Extracting  14.06MB/42.49MB
�[1B2025-10-09 07:45:57.919Z: �[1A2025-10-09 07:45:57.920Z: �[2K
7add29b687fa: Extracting  17.89MB/42.49MB
�[1B2025-10-09 07:45:58.022Z: �[1A�[2K
7add29b687fa: Extracting  25.13MB/42.49MB
�[1B2025-10-09 07:45:58.123Z: �[1A�[2K
7add29b687fa: Extracting  30.24MB/42.49MB
�[1B2025-10-09 07:45:58.256Z: �[1A�[2K
7add29b687fa: Extracting  30.67MB/42.49MB
�[1B2025-10-09 07:45:58.395Z: �[1A�[2K2025-10-09 07:45:58.395Z: 
7add29b687fa: Extracting  31.95MB/42.49MB
�[1B2025-10-09 07:45:58.518Z: �[1A�[2K
7add29b687fa: Extracting   32.8MB/42.49MB
�[1B2025-10-09 07:45:58.631Z: �[1A�[2K
7add29b687fa: Extracting   34.5MB/42.49MB
�[1B2025-10-09 07:45:58.784Z: �[1A�[2K
7add29b687fa: Extracting  37.49MB/42.49MB
�[1B2025-10-09 07:45:58.884Z: �[1A�[2K
7add29b687fa: Extracting  40.47MB/42.49MB
�[1B2025-10-09 07:45:59.039Z: �[1A�[2K2025-10-09 07:45:59.040Z: 
7add29b687fa: Extracting  42.17MB/42.49MB
�[1B2025-10-09 07:45:59.098Z: �[1A�[2K
7add29b687fa: Extracting  42.49MB/42.49MB
�[1B2025-10-09 07:46:00.094Z: �[1A�[2K
7add29b687fa: Pull complete 
�[1B2025-10-09 07:46:00.100Z: Digest: sha256:1f8a1ea669115b1c87835427e89f6278f58a934a2e3f20eca3af7b6366ee5af2
2025-10-09 07:46:00.102Z: Status: Downloaded newer image for mcr.microsoft.com/devcontainers/base:alpine
2025-10-09 07:46:00.528Z: Container started
2025-10-09 07:46:00.705Z: Outcome: success User: vscode WorkspaceFolder: /workspaces/vscode-cmake-tools
2025-10-09 07:46:00.712Z: devcontainer process exited with exit code 0

=================================================================================
2025-10-09 07:46:01.697Z: Running blocking commands...
2025-10-09 07:46:01.742Z: $ devcontainer up --id-label Type=codespaces --workspace-folder /var/lib/docker/codespacemount/workspace/vscode-cmake-tools --mount type=bind,source=/.codespaces/agent/mount/cache,target=/vscode --user-data-folder /var/lib/docker/codespacemount/.persistedshare --container-data-folder .vscode-remote/data/Machine --container-system-data-folder /var/vscode-remote --log-level trace --log-format json --update-remote-user-uid-default never --mount-workspace-git-root false --omit-config-remote-env-from-metadata --skip-non-blocking-commands --expect-existing-container --config "/var/lib/docker/codespacemount/workspace/vscode-cmake-tools/.devcontainer/devcontainer.json" --override-config /root/.codespaces/shared/merged_devcontainer.json --default-user-env-probe loginInteractiveShell --container-session-data-folder /workspaces/.codespaces/.persistedshare/devcontainers-cli/cache --secrets-file /root/.codespaces/shared/user-secrets-envs.json
2025-10-09 07:46:01.945Z: @devcontainers/cli 0.80.0. Node.js v18.20.6. linux 6.8.0-1030-azure x64.
2025-10-09 07:46:02.144Z: Outcome: success User: vscode WorkspaceFolder: /workspaces/vscode-cmake-tools
2025-10-09 07:46:02.159Z: devcontainer process exited with exit code 0

=================================================================================
2025-10-09 07:46:02.165Z: Configuring codespace...

=================================================================================
2025-10-09 07:46:02.165Z: Finished configuring codespace.

Additional Information

No response

[yanghhhhhhh]

@kaladron Thank you for reporting the issue here. We tried to reproduce this issue on VS Code 1.105.0 + Dev Containers 0.427.0. We downloaded Docker, and VS Code connected to Docker properly. Please refer to this video: repro.zip. We were unable to reproduce this issue. Could you help us recheck this issue? In order for us to investigate this further, could you provide us with a sample project and the detailed repro steps? Thank you.