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nix-query-tree-viewer

nix-query-tree-viewer is a convenient way to visualize the output of the dependencies of a given path in the Nix store.

image of nix-query-tree-viewer

This is the same tree information that nix-store --query --tree <PATH> outputs, but nix-query-tree-viewer makes it easier to understand and interact with.

Usage

You can run nix-query-tree-viewer by passing it a path in the Nix store:

$ nix-query-tree-viewer /nix/store/ghzg4kg0sjif58smj2lfm2bdvjwim85y-gcc-wrapper-7.4.0

Installing

nix-query-tree-viewer can be installed with either Nix or Cargo.

Installing with nix-env:

$ nix-env -f channel:nixos-unstable -iA nix-query-tree-viewer

This is convenient if you just want to use nix-query-tree-viewer.

Installing with cargo:

$ cargo install nix-query-tree-viewer

You'll need to have GTK libraries available in your environment for this to work.

Why use `nix-query-tree-viewer`?

The command nix-store --query --tree can be used to see the dependencies of a path in the Nix store in a tree format:

$ nix-store --query --tree /nix/store/ghzg4kg0sjif58smj2lfm2bdvjwim85y-gcc-wrapper-7.4.0
/nix/store/ghzg4kg0sjif58smj2lfm2bdvjwim85y-gcc-wrapper-7.4.0
+---/nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27
|   +---/nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27 [...]
+---/nix/store/cinw572b38aln37glr0zb8lxwrgaffl4-bash-4.4-p23
|   +---/nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27 [...]
|   +---/nix/store/cinw572b38aln37glr0zb8lxwrgaffl4-bash-4.4-p23 [...]
+---/nix/store/hlnxw4k6931bachvg5sv0cyaissimswb-gcc-7.4.0-lib
|   +---/nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27 [...]
|   +---/nix/store/hlnxw4k6931bachvg5sv0cyaissimswb-gcc-7.4.0-lib [...]
+---/nix/store/f5wl80zkrd3fc1jxsljmnpn7y02lz6v1-glibc-2.27-bin
|   +---/nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27 [...]
...

This is fine for simple derivations, but it gets very complicated for paths with deep dependency trees.

nix-query-tree-viewer helps with this by folding branches of the tree by default. Clicking on a branch allows you to drill down into interesting branches.

For example, here is the same picture as above, but with two of the branches open:

image of nix-query-tree-viewer with two branches open

Finding Paths for Derivations

You can use nix-build and nix-instantiate to easily find the paths for derivations.

For instance, if you want to find the path of gcc in the Nix store, you can use nix-build:

$ nix-build '<nixpkgs>' -A gcc --no-out-link
...
/nix/store/ghzg4kg0sjif58smj2lfm2bdvjwim85y-gcc-wrapper-7.4.0

If you want to find the path of the .drv file for gcc, you can use nix-instantiate:

$ nix-instantiate '<nixpkgs>' -A gcc
...
/nix/store/dyxdjxyszmlz29mb0jr9qkncj5l41dai-gcc-wrapper-7.4.0.drv

You should be able to pass both /nix/store/ghzg4kg0sjif58smj2lfm2bdvjwim85y-gcc-wrapper-7.4.0 and /nix/store/dyxdjxyszmlz29mb0jr9qkncj5l41dai-gcc-wrapper-7.4.0.drv to nix-query-tree-viewer.

In general, passing the output of nix-build to nix-query-tree-viewer will let you see the run-time dependencies of a derivation, while passing the output of nix-instantiate will let you see the build-time dependencies of a derivation.

Contributions

Feel free to open an issue or PR for any bugs/problems/suggestions/improvements.

Development

You can get into a development environment by running nix-shell.

This nix-shell provides the necessary system libraries for building, as well as rustup.

rustup can be used to fetch the latest Rust compiler, as well as related tools:

$ rustup toolchain install 1.55.0

You should now have cargo and rustc, which can be used for building the project:

$ cargo build