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I've standardized on getting github actions to create/pull a docker image and run build/test inside that. So if something goes wrong I have a decent live debug environment that's very similar to what github actions is running. For what it's worth.

I do the same with Nix as it works for macOS builds as well

It has the massive benefit of solving the lock-in problem. Your workflow is generally very short so it is easy to move to an alternative CI if (for example) Github were to jack up their prices for self hosted runners...

That said, when using it in this way I personally love Github actions

Nix is so nice that you can put almost your entire workflow into a check or package. Like your code-coverage report step(s) become a package that you build (I'm not brave enough to do this)

I run my own jenkins for personal stuff on top of nixos, all jobs run inside devenv shell, devenv handles whatever background services required (i.e. database), /nix/store is shared between workers + attic cache in local network.

Oh, and there is also nixosModule that is tested in the VM that also smoke tests the service.

First build might take some time, but all future jobs run fast. The same can be done on GHA, but on github-hosted runners you can't get shared /nix/store.

I'm scared by all these references to nix in the replies here. Sounds like I'm going to have learn nix. Sounds hard.

Gemini/ChatGPT help (a lot) when getting going. They make up for the poor documentation

LLMs are awful at nix in my experience. Just learn the fundamentals of the language and build something with it.

Calling nix documentation poor is an insult to actually poor documentation.

Remember the old meme image about Vim and Emacs learning curves? Nix is both of those combined.

It's like custom made for me on the idea level, declarative everything? Sign me up!

But holy crap I have wasted so much time and messed up a few laptops completely trying to make sense of it :D

Whata the killer benefit of nix over, like, a docker file or a package.lock or whatever?

package.lock is JSON only, Nix is for the entire system, similar to a Dockerfile

Nix specifies dependencies declaritively, and more precisely, than Docker (does by default), so the resulting environment is reproducibly the same. It caches really well and doubles as a package manager.

Despite the initial learning curve, I now personally prefer Nix's declarative style to a Dockerfile

same here. though, i think bazel is better for DAGs. i wish i could use it for my personal project (in conjunction with, and bootstrapped with nix), but that's a pretty serious tooling investment that I just feel is just going to be a rabbit hole.

I tend to have most of my workflows setup as scripts that can run locally in a _scripts diorectory, I've also started to lean on Deno if I need anything more complex than I'm comfortable with in bash (even bash in windows) or powershell, since it executes .ts directly and can refer directly to modules/repos without a separate install step.

This may also leverage docker (compose) to build/run different services depending on the stage of action. Sometimes also creating "builder" containers that will have a mount point for src and output to build and output the project in different OSes, etc. Docker + QEMU allows for some nice cross-compile options.

The less I rely on Github Actions environment the happier I am... the main points of use are checkout, deno runtime, release please and uploading assets in a release.

It sucks that the process is less connected and slow, but ensuring as much as reasonable can run locally goes a very long way.

I just use the fact that any action run can trigger a webhook.

The action does nothing other than trigger the hook.

Then my server catches the hook and can do whatever I want.

I wish I had the courage to run my own CI server. But yes, I think your approach is the best for serious teams that can manage more infrastructure.

I am embarrassed that I didn't think to do this. Thank you :)

I was doing something similar when moving from Earthly. But I have since moved to Nix to manage the environment. It is a lot better of a developer experience and faster! I would checkout an environment manager like Nix/Mise etc so you can have the same tools etc locally and on CI.

Yeah, images seem to work very well as an abstraction layer for most CI/CD users. It's kind of unfortunate that they don't (can't) fully generalize across Windows and macOS runners as well, though, since in practice that's where a lot of people start to get snagged by needing to do things in GitHub Actions versus using GitHub Actions as an execution layer.

I’ve VNCed into CI to debug selenium tests failing because of platform font and scrollbar rendering. I never really thought about doing that locally in a docker container, but it definitely wouldn’t be convenient to always run those tests locally in a docker container. I guess having an option to would sort of simplify debugging, but I’d still have to VNC into the docker container I think

Me, too, though getting the trusted publisher NPM settings working didn't help with this. But it does help with most other CI issues.

Most of the npm modules I've built are fortunately pretty much just feature complete... I haven't had to deal with that in a while...

I do have plans to create a couple libraries in the near future so will have to work through the pain(s)... also wanting to publish to jsr for it.

So you've implemented GitLab CI in GitHub... We used to do this in Jenkins like 7 years ago.

https://github.com/nektos/act

Lets you run your actions locally. I've had significant success with it for fast local feedback.

I tried this five years ago back when I was an engineer on the PyTorch project, and it didn't work well enough to be worth it. Has it improved since then?

It works well enough that I didn’t realize this wasn’t first party till right now.

It works, but there are fair amount of caveats, especially for someone working on things like Pytorch, the runtime is close but not the same, and its support of certain architectures etc can create annoying bugs.

For me, no. Spend days trying to get it to recreate a production environment workflow. It is too different than production.

it has. it's improved to work with ~ 75% of steps . fast enough to worth trying before push

I tried this recently and it seems like you have to make a lot of decisions to support Act. It in no way "just works", but instead requires writing actions knowing that they'll run on Act.

I tried act, on the surface it seems like a godsend. Not until you try to use it do you realize it's almost impossible to recreate any moderately complex workflow.

You HAVE to run it against a container, so if you're using self hosted runners your environment may not match at all.

It's insane to me that being able to run CI steps locally is not the first priority of every CI system. It ought to be a basic requirement.

I've often thought about this. There are times I would rather have CI run locally, and use my PGP signature to add a git note to the commit. Something like:

``` echo "CI passed" | gpg2 --clearsign --output=- | git notes add -F- ```

Then CI could check git notes and check the dev signature, and skip the workflow/pipeline if correctly signed. With more local CI, the incentive may shift to buying devs fancier machines instead of spending that money on cloud CI. I bet most devs have extra cores to spare and would not mind having a beefier dev machine.

I think this is a sound approach, but I do see one legitimate reason to keep using a third-party CI service: reducing the chance of a software supply chain attack by building in a hardened environment that has (presumably) had attention from security people. I'd say the importance of this is increasing.

"Works on my machine!"

This goes against every incentive for the CI service provider

Not necessarily. For example, Buildkite lets you host your own runners.

https://github.com/nektos/act

> i.e. the lack of a tight feedback loop.

Lefthook helps a lot https://anttiharju.dev/a/1#pre-commit-hooks-are-useful

Thing is that people are not willing to invest in it due to bad experiences with various git hooks, but there are ways to have it be excellent

Yeah, I'm one of those people who seems to consistently have middling-to-bad experiences with Git hooks (and Git hook managers). I think the bigger issue is that even with consistent developer tooling between both developer machines and CI, you still have the issue where CI needs to do a lot more stuff that local machines just can't/won't do (like matrix builds).

Those things are fundamentally remote and kind of annoying to debug, but GitHub could invest a lot more in reducing the frustration involved in getting a fast remote cycle set up.

GitHub could invest a lot more in actions for sure. Even just in basic stuff like actions/checkout@v6 being broken for self-hosted runners.

But very often the CI operations _are_ the problem. It's just YAML files with unlimited configuration options that have very limited documentation, without any type of LSP.

We need SSH access to the failed instances so we can poke around and iterate from any step in the workflow.

Production runs should be immutable, but we should be able to get in to diagnose, edit, and retry. It'd lead to faster diagnosis, resolution, and fixing.

The logs and everything should be there for us.

And speaking of the logs situation, the GHA logs are really buggy sometimes. They don't load about half of the time I need them to.

I wrote something recently with webrtc to get terminal on failure: https://blog.gripdev.xyz/2026/01/10/actions-terminal-on-fail...

Are there solutions to this like https://github.com/marketplace/actions/ssh-to-github-action-... ?

This is one of the big problems we solved with the RWX CI platform (RWX.com). You can use ‘rwx run’ and it automatically syncs your local changes, so no need to push — and with our automated caching, steps like setting up the environment cache hit so you don’t have to execute the same stuff over and over again while writing your workflow. Plus with our API or MCP server you can get the results directly in your terminal so no need to open the UI at all unless you want to do some in-depth spelunking.

I’ve contemplated building my own CI tool (with a local runner) and the thing is if you assume “write a pipeline that runs locally but also on push”, then the feature depth is mostly about queuing, analyzing output, and often left off, but IMO important, charting telemetry about the build history.

Most of these are off the shelf, at least in some programming languages. It’s the integrations and the overmanagement where a lot of the weight is.

I think you described Jenkins, which is infinitely better than GitHub runners.

Jenkins has it's own set of issues. The theory behind GHA is you *should* be able to keep everything in git and not need a another service with it's own abstractions.

But Actions just screws this up. I consider them both to be equally bad.

I'm almost considering n8n to replace both but that will just lead to more problems.

All my Jenkins builds are between 1 and 3 lines depending on readability:

Clone

Cd $clonedFolder

./build.sh

Add an archive step, all set.

I will say even building and running unit testing in Jenkins isn’t bad, but if you aren’t careful it can get messy.

Jenkins can be a super simple build tool. Strong-arming it into doing all the things starts to get messy quickly. Build, run unit tests, archive. I’m not even big on like, building on push. Nothing wrong with it, I’m just big on keeping things as simple as possible. GHA is just a ball of complexity.

I've never used gh workflow run, but I have used the GitHub API to run workflows and wanted to show the URL. I had to have it make another call to get the workflow runs and assume the last run is the one with the correct URL. This would obviously not work correctly if there were multiple run requests at the same time. Maybe some more checking could detect that, but it works for my purposes so far.

Does the metadata in the further call not identify the branch/start time/some other useful info that could help disambiguate this? (honest question)

I wonder what prevents a GH action from connecting to your VPN (Wireguard is fine) and post tons of diagnostics right onto your screen, and then, when something goes badly wrong, or when a certain point is reached, to just keep polling an HTTP endpoint for shell commands to execute.

I mean. I understand, it would time out eventually. But it may be enough time to interactively check a few things right inside the running task's process.

Of course this should only happen if the PR contains a file that says where to connect and when to stop for interactive input. You would only push such a file when an action is misbehaving, and you want to debug it.

I understand that it's a band-aid, but a band-aid is better than the nothing which is available right now.

I’ve never used Nix and frankly am a sceptic, but can it solve this problem by efficiently caching steps?