Dev Container features

The features this repository builds, and the upstream ones they pull in.

The container images are assembled from Dev Container features rather than a hand-written Dockerfile. Six of them are local to this repository, under .github/.devcontainer/, and the rest come from upstream registries.

They are ordered through installsAfter, so the graph resolves to: common utilities and Git, then the language runtimes and their packages, then uv, Chrome, Decktape, the Quarto CLI, TinyTeX, the GitHub CLI, and finally the cleanup pass.

Local features

`quarto-computing-dependencies`

Installs the R, Python, and Julia packages Quarto needs to render computations. It declares dependsOn for the runtimes themselves, so requesting this one feature brings in R, Python, and Julia.

Option	Default	Description
`installOnPlatforms`	`amd64,arm64`	Architectures to install on; other architectures are skipped with a message rather than failing.
`rDeps`	`rmarkdown`	Comma-separated R packages, installed with `pak::pkg_install()`.
`pythonDeps`	`jupyter,papermill`	Comma-separated Python packages, installed with `pip`.
`juliaDeps`	`IJulia`	Comma-separated Julia packages, installed with `Pkg.add()`.

Runtime dependencies, each pinned to its release channel:

ghcr.io/rocker-org/devcontainer-features/r-rig:1 with installREnv: true and without the extra R tooling, since rmarkdown is installed through rDeps instead.
ghcr.io/devcontainers/features/python:1 with enableShared: true, which the R reticulate and Quarto Jupyter paths need.
ghcr.io/julialang/devcontainer-features/julia:1 on the release channel.

R and Julia packages are installed as the remote user, so they land in that user’s library rather than the system one.

`uv`

Installs uv into /usr/local/bin from the official installer, and registers Zsh completions.

Option	Default	Description
`version`	`latest`	`latest`, or a release tag from the `astral-sh/uv` repository.

`chrome`

Provides a headless browser for Typst previews, Mermaid diagrams, and Decktape.

On amd64 it installs Google Chrome from Google’s apt repository. On arm64, where Google publishes no package, it installs Chromium through Playwright. Both paths expose the browser at /usr/local/bin/chromium, and the feature sets two environment variables so Quarto and Puppeteer find it without configuration:

{
  "PUPPETEER_EXECUTABLE_PATH": "/usr/local/bin/chromium",
  "QUARTO_CHROMIUM": "/usr/local/bin/chromium"
}

This is why quarto check reports Chrome from QUARTO_CHROMIUM rather than Quarto’s own headless shell download.

`decktape`

Installs Node.js from NodeSource and Decktape globally, for turning HTML presentations into PDF.

Option	Default	Description
`version`	`22`	Node.js major version.

Puppeteer’s bundled Chromium download is disabled; Decktape uses the browser from the chrome feature instead, which keeps the image smaller and works on arm64.

`tinytex`

Installs TinyTeX into /opt/tinytex from the upstream installer, links tlmgr and the LaTeX binaries into /usr/local/bin, and creates a tinytex group so the remote user can install packages at runtime without sudo. It also runs tlmgr init-usertree for that user.

Because TinyTeX is installed outside Quarto’s own tree, quarto check reports it as (external install).

`cleanup`

Runs last and reclaims space before the image is committed: user caches (.cache, .npm, .R, .julia/logs, .julia/compiled, Yarn, Trash), /tmp, apt lists, and the pip, uv, and npm caches, plus the TinyTeX package database backups.

It has no options and is safe to omit; leaving it out only makes the image larger.

Upstream features

Feature	Configured with
`ghcr.io/devcontainers/features/common-utils:2`	Zsh, the remote user, `upgradePackages: true`
`ghcr.io/devcontainers/features/git:1`	`latest`, no PPA
`ghcr.io/rocker-org/devcontainer-features/quarto-cli:1`	version from the build matrix, with TinyTeX and Chromium installation disabled
`ghcr.io/devcontainers/features/github-cli:1`	`latest`

The quarto-cli feature is told not to install TinyTeX or Chromium because the tinytex and chrome features already provide them, on both architectures.

Duplication in the universal configuration

.devcontainer/universal/ keeps its own copies of quarto-computing-dependencies and uv, because a Dev Container configuration can only reference local features inside its own context directory.

The check-feature-sync job in the build workflow runs diff -r between the two pairs of directories and fails the build if they drift. When you change one, change the other identically.