overthinkos/language-runtimes

language-runtimes -- Go, PHP, .NET, nodejs-devel, python3-devel

Layer Properties

| Property | Value | |----------|-------| | Dependencies | nodejs, rust | | Install files | layer.yml (packages only) |

Packages (RPM)

• dotnet-sdk-9.0 — Microsoft .NET 9 SDK (~600 MB, dominant size)
• golang-bin — Go compiler + standard library
• golang-bazil-fuse-devel — Go FUSE bindings (for layers compiling FUSE Go code)
• libicu — ICU i18n library (required by .NET)
• php — PHP CLI + core modules
• python3-devel — system Python 3 + dev headers
• python3-ramalama — RamaLama tool (Python)
• nodejs-devel — Node.js headers (some native-module compiles need this alongside the nodejs layer's runtime)

Packages (pac) — Arch Linux

• dotnet-sdk — in [extra] (no third-party repo needed)
• go, icu, php, python — all [core] / [extra]. Arch ships headers with the main package (no -devel split), so nodejs-devel / python3-devel have no separate pac: entries.

Drops on Arch: python3-ramalama (not packaged — install via uv tool install ramalama), golang-bazil-fuse-devel (Go library fetched via go get).

Packages (deb) — Debian + Ubuntu

• golang-go — Go compiler + stdlib
• libicu-dev — ICU with dev headers
• php-cli — PHP CLI binary (Debian splits php into php-cli / php-fpm / etc.)
• python3-dev — system Python 3 + dev headers

dotnet-sdk-9.0 is not in the deb: package list. It's installed by a cross-distro cmd: task via Microsoft's official dotnet-install.sh — see the next subsection. python3-ramalama, golang-bazil-fuse-devel, nodejs-devel are dropped (not packaged on Debian/Ubuntu).

dotnet-sdk-9.0 via Microsoft's dotnet-install.sh (2026-04)

Cross-distro parity for .NET 9 requires juggling three asymmetric availability windows:

| Distro | Where dotnet-sdk-9.0 lives | |---|---| | Fedora 43 | Distro repo (rpm: pulls dotnet-sdk-9.0) | | Arch | [extra] (pac: pulls dotnet-sdk) | | Debian 13 trixie | Microsoft's trixie apt repo has it; Debian main does not | | Ubuntu 24.04 noble | Neither Canonical noble (ships 8.0 + 10.0) nor Microsoft's noble apt repo (ships only 10.0) has 9.0 |

Rather than carrying that asymmetry in layer code, the layer uses Microsoft's official cross-distro installer script, channel-pinned to 9.0. It installs to /usr/share/dotnet and symlinks /usr/bin/dotnet:

tasks:
  - cmd: |
      if command -v dotnet >/dev/null 2>&1; then
        exit 0                        # already installed by distro rpm/pac
      fi
      if ! command -v apt-get >/dev/null 2>&1; then
        exit 0                        # non-Debian-family + no dotnet — intentional drop
      fi
      install -d /usr/share/dotnet
      curl -fsSL https://builds.dotnet.microsoft.com/dotnet/scripts/v1/dotnet-install.sh -o /tmp/dotnet-install.sh
      chmod +x /tmp/dotnet-install.sh
      /tmp/dotnet-install.sh --channel 9.0 --install-dir /usr/share/dotnet
      ln -sf /usr/share/dotnet/dotnet /usr/bin/dotnet
      rm -f /tmp/dotnet-install.sh
    user: root

Verified 2026-04-20 on ghcr.io/overthinkos/ubuntu-coder:latest:

$ /usr/bin/dotnet --version
9.0.313

Idempotent: the outer command -v dotnet guard makes this task a no-op on Fedora/Arch (where the distro package already installed dotnet) and on rebuilds (where the previous run already placed the symlink). Runtime dependency: libicu-dev (already installed by the layer's deb: section).

See /ov:layer for general cross-distro task-authoring patterns.

Tag-section overrides

• debian:13: — just packages (same as generic deb:).
• ubuntu:24.04: — just packages (same as generic deb:).

Both exist so future Microsoft-apt-repo-based installs can be slotted into tag sections via repos: + packages: without disturbing the generic deb: fallback.

The vestigial depends: python removed in 2026-04

The layer used to declare depends: python, pulling in the python ov-layer → pixi ov-layer → a conda-forge Python env (~500 MB). But this layer installs python3-devel + python3-ramalama via RPM — system Python. The pixi-python env was never referenced by anything this layer installs. The dep was dropped in 2026-04; consumers of language-runtimes now get only the RPM Python stack.

Consequence for /ov-images:fedora-coder (the biggest consumer): the whole python / pixi ov-layer chain drops out of the resolved layer set (since /ov-layers:uv also dropped its vestigial python dep and /ov-layers:supervisord also removed its). Image size dropped by several hundred MB. See CLAUDE.md "Key Rules" → "Don't declare defensive deps" for the general rule.

If you genuinely need the pixi-python env (e.g. a layer that installs a Python package from conda-forge via pixi), declare depends: python on THAT layer directly — don't rely on transitive pulls.

Tests

Six build-scope tests ship with the layer:

| Test | Purpose | |---|---| | dotnet-binary + dotnet-version | .NET SDK installed and responsive | | php-binary + php-version | PHP CLI reachable | | system-python3 + system-python3-version | /usr/bin/python3 is the system interpreter (the RPM-installed one; explicitly NOT a pixi-env path) |

Go and Node.js testing is delegated to the /ov-layers:golang and /ov-layers:nodejs / /ov-layers:nodejs24 layer skills — those are the single sources of truth for their respective binaries.

Usage

# image.yml
my-polyglot:
  layers:
    - language-runtimes

Used In Images

• /ov-images:fedora-coder — kitchen-sink dev image, canonical RPM consumer.
• /ov-images:arch-coder — pacman-based sibling.
• /ov-images:debian-coder, /ov-images:ubuntu-coder — deb-based siblings, consumers of the dotnet-install.sh task.
• /ov-images:bazzite-ai (disabled).

Related Layers

• /ov-layers:nodejs — Node.js runtime (direct dependency)
• /ov-layers:rust — Rust toolchain (direct dependency)
• /ov-layers:python — Pixi-python env. Not a dep of this layer as of 2026-04.
• /ov-layers:golang — Go toolchain (may be added separately for clarity even though golang-bin is already in this layer's RPM list)
• /ov-layers:uv — direct-download Rust binary (also dropped its vestigial pixi-python dep in 2026-04)

Related Commands

• /ov:layer — authoring reference (tag-section cascade, cmd: vs declarative repos)
• /ov:build — base_user: and bootstrap packages
• /ov:shell — verify runtimes inside a container

When to Use This Skill

MUST be invoked when:

• Composing language-runtimes into an image.
• Debating pixi-python vs. system python3 — this layer is the canonical "system python3 only" example.
• Understanding why the python ov-layer is missing from an image that uses language-runtimes (that's by design since 2026-04).

Related

• /ov:test — declarative testing (tests: block, ov image test, ov test)