flake: partition dev inputs

[0xda157]

follow up to #1208
cc @trueNAHO @MattSturgeon

Things done

• Tested locally
• Tested in testbed
• Commit message follows commit convention
• Fits style guide
• Respects license of any existing code used

Notify maintainers

[0xda157]

currently marked as a draft because the testbed logic needs to be refactored to enable flake-parts to see what testbeds exist as mentioned in #1208 (comment). not entirely sure how to go about that, would probably be best to do in a separate pr.

[MattSturgeon]

currently marked as a draft because the testbed logic needs to be refactored to enable flake-parts to see what testbeds exist as mentioned in #1208 (comment). not entirely sure how to go about that, would probably be best to do in a separate pr.

My vague idea is to split testbed.nix's autoload into two stages.

Stage 1 collects the testbed modules and forms them into an attrset of {name → module}. This bit is needed in the top-level flake configuration.

Stage 2 maps those modules into nixos VM systems. This is done in the dev partition.

This would probably need to be done in separate files, as otherwise it'll be difficult to call the testbed.nix file from the flake, without supplying inputs needed for Stage 2.

[0xda157]

My vague idea is to split testbed.nix's autoload into two stages.

Stage 1 collects the testbed modules and forms them into an attrset of {name → module}. This bit is needed in the top-level flake configuration.

Stage 2 maps those modules into nixos VM systems. This is done in the dev partition.

This would probably need to be done in separate files, as otherwise it'll be difficult to call the testbed.nix file from the flake, without supplying inputs needed for Stage 2.

I think avoiding a major refactor of the testbeds would be a bad idea just because there's a lot of other prs editing it them, hopefully we can get them merged soon.

[MattSturgeon]

Still LGTM

[trueNAHO]

LGTM. Good job, everyone. Great to see this getting merged.

For reference, I have successfully tested this PR in my standalone Home Manager setup:

Tested-by: NAHO <90870942+trueNAHO@users.noreply.github.com>

[stylix-automation]

Backport failed for release-25.05, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin release-25.05
git worktree add -d .worktree/backport-1289-to-release-25.05 origin/release-25.05
cd .worktree/backport-1289-to-release-25.05
git switch --create backport-1289-to-release-25.05
git cherry-pick -x a5c1532ab8bf9566331f83be91517e02132f3d99

[0xda157]

I will take care of the manual backport