Lately I’ve been trying https://devenv.sh/ and it works great!
I haven’t tried it for ruby, though I have used vanilla nix shell for ruby projects before and it worked quite well after I over-rode GEM_PATH and GEM_HOME to the correct values.
Can devenv environment put itself in a chroot / sandbox where it cannot access my files, and is firewalled by default?
nix file helps you build OCI image and then you run it not locally/somewhere else?
can that be compared apples to apples to docker where you can build with Dockerfile syntax, and then run locally the image?
(Aside: you can build oci images using nix, but that’s probably what you would use for building deployable artifacts for production, not for development).
I would not say it is comparable with a Dockerfile - a Dockerfile is closer to a shell script, with caching between each step. Credit to Dockerfile syntax for being very easy to grok, but it is inherently not reproducible.
The perceived reliability of docker for development probably comes from the fact that you can share a prebuilt image, but rebuilding might not always work.