TLDR: A new release will fix the issue :)

The currently released action (v0.12.0) uses DeterminateSystems/nix-installer-action@e50d5f73bfe71c2dd0aa4218de8f4afa59f8f81d # v16.

This version of nix-installer-action uses a decommissioned Github Actions cache service. The issue is already solved in v17: DeterminateSystems/nix-installer-action#167

Previously the cache failures were pretty quite. But 2 days ago the decommissioned servers were shut down: https://github.com/orgs/community/discussions/160793#discussioncomment-13312469

Now the cache server calls timeout and increase the devbox-install-action run time significantly: https://github.com/orgs/community/discussions/160793

I see that nix-installer-action was already updated in the main branch: 22b0f55 But there was no release yet.

I tried updating my workflow to the latest main branch:

uses: jetify-com/devbox-install-action@22b0f5500b14df4ea357ce673fbd4ced940ed6a1

This resolved the issue 🎉