How to set the file extension of a derivation's $out?

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1

I’m aware that the output of a derivation can be a regular file as opposed to a directory, and that some store paths in my Nix store have file extensions like .tgz. What do I have to do in the derivation function arguments to set a custom file extension for my own derivations?

2

Set name to a filename.

3

One semi-artificial restriction here is that you can’t name them with an ending of “.drv”

4

Unless it’s a fixed-output derivation with flat hashing (i.e. hashing the file contents only, not treating it as a NAR), I would always create a directory. Benefits:

  • can always add more files if needed
  • cp ${thing}/${name} bar/ produces bar/${name} without the hash part.