My devenv sandbox

A repo to collect devenv environments, mostly modified from devenv examples.

Current workflow: individual project will be created in the branch.

Environment will be prepared in main, and I will rebase main back to individual branch accordingly.

Prerequisite

• Really nice nix intro

If you haven't install devenv, follow here

Install nix

curl -L https://raw.githubusercontent.com/NixOS/experimental-nix-installer/main/nix-installer.sh | sh -s install

Enable nix flake

touch ~/.config/nix/nix.conf
echo "extra-experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf

Install direnv

# install direnv
curl -sfL https://direnv.net/install.sh | bash
# Add the following line at the end of the ~/.bashrc file:
# eval "$(direnv hook bash)"

• vscode - install mkhl.direnv extension
• (By doing so, vscode ipython notebook can find the virtual env set up correctly)

Install devenv

# install devenv
nix-env -iA devenv -f https://github.com/NixOS/nixpkgs/tarball/nixpkgs-unstable

Upgrade devenv

not so sure, above install use nix-env, but maybe sometime later I use nix profile for something, and nix-env is no longer usable. eventually I do below ...

nix profile list | grep devenv   -A 1 -B2
Index:              0
Store paths:        /nix/store/24yzpf9qjfn599dsq92sllxx3wdnpznr-devenv-1.1

nix profile remove 0 #  the Index from above
nix profile install nixpkgs#devenv -I nixpkgs=channel:unstable

nix profile list | grep devenv   -A 1 -B2
Index:              1
Flake attribute:    legacyPackages.x86_64-linux.devenv
Locked flake URL:   github:NixOS/nixpkgs/eeeb90a1dd3c9bea3afdbc76fd34d0fb2a727c7a
Store paths:        /nix/store/5fm2f0n3839sdh9qlyh8b6ykqlravr9i-devenv-1.3

Devenv quick tips

• devenv shell activates your developer environment.
• devenv test builds your developer environment and makes sure that all checks pass. Useful to run in your continuous integration environment.
• devenv search <NAME> searches packages matching NAME in Nixpkgs input.
• devenv update updates and pins inputs from devenv.yaml into devenv.lock.
• devenv gc deletes unused environments to save disk space.
• devenv up starts processes.

Tips Related to vscode with the environments

C++ projects

For IntelliSense to work and find the path installed in the environment, you need to make workspace from *_env, as the default search path is ${workspaceFolder}/**. (Or you should change .vscode/c_cpp_properties.json's includePath). As devenv will install packages into .devenv/profile

Python projects

Remember to launch the workspace from the *_env folder as well, then for ipython notebook, select the kernel under .devenv/state/bin/python (If you can recreate, better do so to make sure all libs are installed).