(Resolved) Combining different packages into a single package

Hi, Forum. This question is about symlinkJoin and the way nix-env manages user-profiles.

The task I’d like to solve is how to make one big derivation for all the packages I need (approx. 30 packages, including my custom scripts, custom Xfce components, but also Openoffice, chromium, etc.). The idea is to install them atomically with just one nix-env -i command.

I tried to do it with symlinkJoin but soon I found seriosus disadvantages: 1) it failed to deal with share/applications section, so no icons, no .*desktops. 2) It doesn’t honor nix’s propagate-user-env-packages, it doesn’t add Qt5 when needed 3) It doesn’t provide any systematic way to resolve conflicts. Actually, symlinkJoin is built on top of lndir which is very dumb.

So I have to turn my attention to the nix-env itself that solves very same task when managing user-profiles. Do we have the functionality of nix-env at the nixpkgs level, e.g. as a better-than-symlinkJoin library function?

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symlinkJoin is for the cases where the simplest and the most predictable approach is desired; for environment composition there is buildEnv.


Thanks! Exactly what I needed.

What is what you needed? buildEnv? Does that solve all your problems with symlinkJoin?

Yes, buildEnv. Looks like it is a drop-in replacement for symlinkJoin and it solved my problems.

Ref. https://github.com/grwlf/nixcfg/blob/3cefb977761e7342d1d4b667bcd8edb9d997d675/src/pkgs/myenv.nix#L43


What exactly is the difference in behavior between symlinkJoin and buildEnv?

Well, buildEnv follows the propagation pointers. And filters which subderictories to use. And also does something smart about output selection. And has configurable collision handling. And probably something else, but I do not know.

symlinkJoin is maximally-straightforward lndir wraper.

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