pkgs.symlinkJoin

Create a forest of symlinks to the files in paths.

This creates a single derivation that replicates the directory structure of all the input paths.

BEWARE: it may not "work right" when the passed paths contain symlinks to directories.

Examples

Adds symlinks of hello to the current build:

symlinkJoin { name = "myhello"; paths = [ pkgs.hello ]; }

Adds symlinks of hello and stack to the current build and prints "links added":

symlinkJoin { name = "myexample"; paths = [ pkgs.hello pkgs.stack ]; postBuild = "echo links added"; }

This creates a derivation with a directory structure like the following:

/nix/store/sglsr5g079a5235hy29da3mq3hv8sjmm-myexample
|-- bin
|   |-- hello -> /nix/store/qy93dp4a3rqyn2mz63fbxjg228hffwyw-hello-2.10/bin/hello
|   `-- stack -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/bin/stack
`-- share
    |-- bash-completion
    |   `-- completions
    |       `-- stack -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/share/bash-completion/completions/stack
    |-- fish
    |   `-- vendor_completions.d
    |       `-- stack.fish -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/share/fish/vendor_completions.d/stack.fish
...

To create a directory structure from a specific subdirectory of input paths instead of their full trees, you can either append the subdirectory path to each input path, or use the stripPrefix argument to remove the common prefix during linking.

Creates symlinks of tmpfiles.d rules from multiple packages:

symlinkJoin { name = "tmpfiles.d"; paths = [ pkgs.lvm2 pkgs.nix ]; stripPrefix = "/lib/tmpfiles.d"; }

This creates a derivation with a directory structure like the following:

/nix/store/m5s775yicb763hfa133jwml5hwmwzv14-tmpfiles.d
|-- lvm2.conf -> /nix/store/k6js0l5f0zpvrhay49579fj939j77p2w-lvm2-2.03.29/lib/tmpfiles.d/lvm2.conf
`-- nix-daemon.conf -> /nix/store/z4v2s3s3y79fmabhps5hakb3c5dwaj5a-nix-1.33.7/lib/tmpfiles.d/nix-daemon.conf

By default, packages that don't contain the specified subdirectory are silently skipped. Set failOnMissing = true to make the build fail if any input package is missing the subdirectory (this is the default behavior when not using stripPrefix).

symlinkJoin and linkFarm are similar functions, but they output derivations with different structure.

symlinkJoin is used to create a derivation with a familiar directory structure (top-level bin/, share/, etc), but with all actual files being symlinks to the files in the input derivations.

symlinkJoin is used many places in nixpkgs to create a single derivation that appears to contain binaries, libraries, documentation, etc from multiple input derivations.

linkFarm is instead used to create a simple derivation with symlinks to other derivations. A derivation created with linkFarm is often used in CI as a easy way to build multiple derivations at once.

Noogle detected

{
      # Adds the fixed-point style support
      __functor =
        self: fpargs:
        transformDrv (
          constructDrv (
            final:
            let
              previous = if isFunction fpargs then fpargs final else fpargs;
            in
            removeAttrs previous excludeDrvArgNames // extendDrvArgs final previous
          )
        );

      __functionArgs = removeAttrs (
        # Inherit the __functionArgs from the base build helper
        optionalAttrs inheritFunctionArgs (removeAttrs (functionArgs constructDrv) excludeDrvArgNames)
        # Recover the __functionArgs from the derived build helper
        // functionArgs (extendDrvArgs { })
      ) excludeFunctionArgNames;

      inherit
        # Expose to the result build helper.
        constructDrv
        excludeDrvArgNames
        extendDrvArgs
        transformDrv
        ;
    }