---
id: charmcraftcache
version: "0.8.5"
license: unclear
license_treatment: unclear
maintenance: active
---

# charmcraftcache — Fast first-time builds for charmcraft

License: unclear · Maintenance: active · Downloads: 136.0K/mo

## What it is and what it does

charmcraftcache addresses a specific bottleneck in charmcraft builds: by default, charmcraft builds Python package wheels from source rather than downloading pre-built wheels, which is slow on first build. The package works by downloading pre-built wheels from a centralized hub (maintained separately) and populating charmcraft's pip cache before packing, so subsequent builds reuse those wheels.

It is a CLI tool installed via pipx that wraps charmcraft's pack command. It requires charmcraft.yaml to use multi-base shorthand notation (where build-on and build-for are identical), and it works within charmcraft's LXC container model. The tool is most useful in CI environments and on fresh machines where the pip cache is empty.

Use it for:

- Speed up CI charm builds by pre-populating the pip wheel cache with source-built wheels from a shared hub.
- Reduce build time when contributing to a charm on a new development machine.
- Cache wheels across multiple charm platform variants (e.g., ubuntu@22.04:amd64, ubuntu@24.04:arm64) in a single operation.
- Avoid repeated source builds of the same Python dependencies across multiple charm projects.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Accelerates charmcraft builds by pre-downloading and caching Python wheels built from source, reducing first-time build times on new machines and CI runners.

Yes, if you build charms regularly and want faster first-time builds. The tool is actively maintained, has low install friction, and solves a real pain point in charmcraft workflows. The unclear license is a minor concern to verify before production use. Not relevant for non-charmcraft users.

## Install

pip install charmcraftcache
uv add charmcraftcache
poetry add charmcraftcache

## Installing charmcraftcache

Before you install: Low friction install via pipx. Active maintenance with recent commits and no known vulnerabilities. Depends on common, stable packages (packaging, pyyaml, requests, rich, typer).

License in practice: License status is unclear—no SPDX identifier or raw license text is available in the package metadata. Verify the actual license before use in proprietary or restricted contexts.

Quickstart:

pipx install charmcraftcache
ccc add
ccc pack

Requires charmcraft.yaml to use multi-base shorthand notation syntax (e.g., 'ubuntu@22.04:amd64'); build-on/build-for syntax is not supported. Python >= 3.10 required.

Verify before relying:

- Whether the pre-built wheel cache is kept up-to-date for new charm releases and dependencies.
- Performance improvement magnitude compared to standard charmcraft builds in typical CI scenarios.
- Compatibility with charms using C extensions beyond pyyaml.

## Package facts

- License: not declared (unclear)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 136.0K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

charmcraft build cache, charm package build acceleration, python wheel caching, ci build performance, charm dependency caching, charm-ecosystem, build-caching

[View on SkillFed](https://skillfed.io/packages/charmcraftcache) · [View on PyPI](https://pypi.org/project/charmcraftcache/)