Sure, nixos is very forgiving to experiment with because you can easily rollback to a pervious configuration. Modify a library and something stops working fixing it is as simple as `nix-env --rollback` for a user package and `nixos-rebuild --rollback` if something was changed with the system configuration a restart may be needed if some systems are touched but it has not happened often and when it is needed it is specified.

I enjoy how easy it is to set up different profiles with different sets of libraries/compilers for development.

It has made it worth while to try out old libraries that only work on old compilers. It also made it easier for me to test against the HEAD of the complier repo for testing forward compatibility or new compiler features.

Since everything is nicely encapsulated once I have an environment working on my laptop I can use `nix-copy-closure` to move it to another remote server. `Nixops` a more recent offering just renamed from `charon` also allows for deterministic building of ec2 instances.

took me a while to figure out. nix-env -qa * | grep "package you are looking for" nix-env -i "package"

need to add different channels if you are grabbing packages from places other than nix-pkgs.

I had a hard time, getting some haskell packages to work, because nixos symlinks all the binaries, and there was some encryption library dependency, hard coded in a cabal file, and it was a headache/ gave up.

Eelco also provides a pathelf utility for modifiying dynamic linker in elf files, I haven't used it.

I'm on ubuntu again but I can't remember why. Oh ya, I couldn't get Blackberry's SDK working on nixos. Anything that doesn't go through nix-pkgs, will take some work. I didn't get to the point where I was writing nix-expressions.

If you run it in a VM (KVM/QEMU) you might need to set some CPU flags for the VM (otherwise GMP will assume your CPU has some instructions that it doesn't actually have in the VM): https://github.com/NixOS/nixos/issues/120#issuecomment-14776...

Other than that it works fairly well (in a VM), and you don't need to wait for it to compile all the packages like with Gentoo: if the build server has a binary then it will download that.