Switch Linux local development to Nix

[yakimant]

Description

After creating a Nix build configuration and CI job (see #9350) - developers continue to build locally without Nix.

We need to change that. The benefits are:

• Qt 5 upgrades (original goal)
• Out of the box development environment (no buid deps requirements, no docker,..), shared with CI
• Potentially - shared Linux, macOS, Windows environment

Acceptance Criteria

• Make sure developers build locally with Nix
• Make sure all the Linux Makefile tasks continue to work (original PR was only tested on update, deps, status-go, tgz-linux targets)

[yakimant]

Trying the SHELL env var approach issues:

1. Option 1: global
2. Option 2: per target

Option3: require to run nix-shell before make:

• break certain make targets if not in Nix shell
• easy way to install Nix
• easy way to run Nix shell
• documentation, announcement
• maybe using direnv + flakes

Issues:

Option 1:

• SHELL applies to each $(shell) run and each target command - so nix-shell gets invokes many times
• targets.mk - update-common: invokes + "$(MAKE)", which probably runs make outside of nix - breaks

Option 2:

• $(shell): need to use global SHELL or rewrite ifeq and setting vars logic

Option 3:

[yakimant]

Solution for running nix-shell for each $(shell) invocation:

Use non-nix sh funciton where possible: https://github.com/status-im/status-go/blob/557c4f7e8fb2fb5572d9dc0754c6e7a3243f4d48/Makefile#L97-L102

Another solution to switch to flakes, so nix develop will run much faster (due to derivation caching).
Problem with flakes is secrets storing in case of derivation, which will require injection. But it's not related to shells.

[yakimant]

Need to talk to Nimbus and Desktop teams:

• switch from nimbus-build-system for Nim compile.
• why do we build Nim compiler?
• nimble instead? nixpkgs instead?
• Desktop Makefile guide
  • targets
  • nimbus-build-system
  • removing make targets
  • move long code to separate script file
  • documentation, comments, sections, help target

[yakimant]

nimbus-build-system doc:
https://github.com/status-im/nimbus-build-system

[yakimant]

Meeting with Igor on Desktop Makefile:

• nimbus-build-system used for Nim and Nim dependencies compilation, added through vendor submodules. It's not pleasant to work with, devs would be happy to get rid of it. Maybe Nimble to replace?
• targets are split into groups
  • run: building and running the apps
  • nim_status_client: build app and deps
  • nim_status_client deps: split into dep specific buckets
  • packages: exe, appimage, dmg
  • storybook: separate app to test UI
  • Nim tests
• developers are 50/50 on Linux/macOS
• status-go issue: not being rebuilt if source code changed

Options to improve the Makefile:

• Separate big target groups into separate imported makfiles
• Separate longer targets to shell script files
• Would be great to smth Mobile has - annotating each target with description and help target to list all

Option to improve make&nix-shell experience - switch to flake devShell, which runs much faster.

[yakimant]

Trying to switch Linux builds to Nix shell completely:

• Use nix shell #16359