Create Flake.nix for Nix users

[lambdachad]

This provides a flake.nix so Nix users can easily build and instally this library like so:

• nix build github:remoteoss/dexter
• nix profile install github:remoteoss/dexter
• Adding github:remoteoss/dexter as input to flake.nix and installing it with by adding package as dexter.packages.x86_64-linux.default

[anddani]

I would suggest vendoring all go dependencies in dexter in order to avoid having to update the vendorHash.

I made an attempt at this previously but encountered some issues with one of the dependencies (treesitter I believe). It referenced some .c file with a relative import and the nix build failed.

[JesseHerrick]

Thanks for the contribution @lambdachad! I have never used Nix before, so I definitely appreciate the advice from @anddani. I'll see if some colleagues can take a look and I'll also see about trying this.

Now that we have the tokenizer, I think we might be able to replace tree-sitter with it and remove the dependency, so that might not be a problem in the future.

Is there any way we can automate version bumps in Nix? If not, we should also add logic to the release make task to do this.

[anddani]

For a flake, the exact version is not semantically important since you always reference flake inputs by their revision (when a git repo is referenced).

[anddani]

Suggested change

	version = "0.6.0";
	version = self.shortRev or self.dirtyRev or "dev";

[anddani]

Regarding vendoring.

When I set vendorHash = null; and commit the vendored dependencies, I get the following error when running nix build:

error: Cannot build '/nix/store/2083h6pjkqplgh3y5sqdgm2lnnpfrbp5-dexter-68598bb.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/xbh71mz62ga9anw3pqz0zkg72cs72gwg-dexter-68598bb
       Last 20 log lines:
       > Running phase: unpackPhase
       > unpacking source archive /nix/store/hx63hkdly29snaq0wqschihv1bcn924x-nq20hc2yp9zzha93drpzwi83hmympmpg-source
       > source root is nq20hc2yp9zzha93drpzwi83hmympmpg-source
       > Running phase: patchPhase
       > Running phase: updateAutotoolsGnuConfigScriptsPhase
       > Running phase: configurePhase
       > Running phase: buildPhase
       > Building subPackage .
       > github.com/remoteoss/dexter: no non-test Go files in /nix/var/nix/builds/nix-build-dexter-68598bb.drv-87833-2022350038/nq20hc2yp9zzha93drpzwi83hmympmpg-source
       > Building subPackage ./cmd
       > # github.com/tree-sitter/tree-sitter-elixir/bindings/go
       > vendor/github.com/tree-sitter/tree-sitter-elixir/bindings/go/binding.go:4:11: fatal error: '../../src/parser.c' file not found
       >     4 |  #include "../../src/parser.c"
       >       |           ^~~~~~~~~~~~~~~~~~~~
       > 1 error generated.
       > # github.com/tree-sitter/go-tree-sitter
       > vendor/github.com/tree-sitter/go-tree-sitter/tree_cursor.go:5:10: fatal error: 'tree_sitter/api.h' file not found
       >     5 | #include <tree_sitter/api.h>
       >       |          ^~~~~~~~~~~~~~~~~~~
       > 1 error generated.
       For full logs, run:
         nix log /nix/store/2083h6pjkqplgh3y5sqdgm2lnnpfrbp5-dexter-68598bb.drv

I am not familiar with Go so I am not sure what the best course of action would be. I'll see if I can find some examples from other projects. But I think that if you are about to remove the treesitter Go dependency, this won't be a problem anymore.

[lambdachad]

Yeah this error is why I had to include the modules like I did in the initial example. The tree sitter requires dependencies that aren't included by default.

[lambdachad]

If tree sitter is removed then the flake.nix becomes really simple and easy to maintain.