Update the Nix setup to rely on the Coq Nix Toolbox.

Use the dynamic workflow generation.

.github/workflows/nix-action.yml

@@ -0,0 +1,49 @@
+# This file was generated from `meta.yml`, please do not edit manually.
+# Follow the instructions on https://github.com/coq-community/templates to regenerate.
+name: Nix CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  setup:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Do nothing
+      run: echo "No setup, using meta.yml bundles"
+  "aac-tactics":
+    name: Main build
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        bundle:
+          - default
+    steps:
+    - name: Cachix install
+      uses: cachix/install-nix-action@v12
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq
+      uses: cachix/cachix-action@v8
+      with:
+        # Name of a cachix cache to pull/substitute
+        name: coq
+    - name: Cachix setup coq-community
+      uses: cachix/cachix-action@v8
+      with:
+        # Name of a cachix cache to pull/substitute
+        name: coq-community
+        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+    - name: Git checkout
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - name: Building/fetching dependencies
+      run: nix-build --no-out-link --argstr bundle "${{ matrix.bundle }}" --argstr job "_deps"
+    - name: Building/fetching current project
+      run: nix-build --no-out-link --argstr bundle "${{ matrix.bundle }}" --argstr job "aac-tactics"

.nix/coq-nix-toolbox.nix

@@ -0,0 +1,3 @@
+# This file was generated from meta.yml, please do not edit manually.
+# Follow the instructions on https://github.com/coq-community/templates to regenerate.
+"a0c0f3d7deddacbe4575ac3c3c63f43dd103c175"

.nix/fallback-config.nix

@@ -0,0 +1,47 @@
+# This file was generated from `meta.yml`, please do not edit manually.
+# Follow the instructions on https://github.com/coq-community/templates to regenerate.
+
+# *However*, you may copy paste it to `config.nix`
+# in the same subdirectory .nix and extend it as needed.
+# Note that this would completely deactivate this file.
+
+{
+  ## DO NOT CHANGE THE format
+  format = "1.0.0";
+  ## unless you made an automated or manual update
+  ## to another supported format.
+
+  ## The attribute to build, either from nixpkgs
+  ## of from the overlays located in `.nix/coq-overlays`
+  attribute = "aac-tactics";
+
+  ## If you want to select a different attribute
+  ## to serve as a basis for nix-shell edit this
+  # shell-attribute = "aac-tactics";
+
+  ## Maybe the shortname of the library is different from
+  ## the name of the nixpkgs attribute, if so, set it here:
+  pname = "aac-tactics";
+
+  ## Lists the dependencies, phrased in terms of nix attributes.
+  ## No need to list Coq, it is already included.
+  ## These dependencies will systematically be added to the currently
+  ## known dependencies, if any more than Coq.
+  ## /!\ Remove this field as soon as the package is available on nixpkgs.
+  ## /!\ Manual overlays in `.nix/coq-overlays` should be preferred then.
+  #buildInputs = [ ];
+
+  ## Indicate the relative location of your _CoqProject
+  ## If not specified, it defaults to "_CoqProject"
+  coqproject = "_CoqProject";
+
+  ## Select a bundle to build by default in the following `bundles` set
+  ## It will be used when typing nix-shell or nix-build without argument
+  ## defaults to "default"
+  default-bundle = "default";
+  bundles."default" = {};
+
+  bundles."default" = {
+      coqPackages."coq".override.version = "master";
+  };
+}

default.nix

@@ -1,31 +1,13 @@
 # This file was generated from `meta.yml`, please do not edit manually.
 # Follow the instructions on https://github.com/coq-community/templates to regenerate.
-
-{ pkgs ? (import <nixpkgs> {}), coq-version-or-url, shell ? false }:
-
-let
-  coq-version-parts = builtins.match "([0-9]+).([0-9]+)" coq-version-or-url;
-  coqPackages =
-    if coq-version-parts == null then
-      pkgs.mkCoqPackages (import (fetchTarball coq-version-or-url) {})
-    else
-      pkgs."coqPackages_${builtins.concatStringsSep "_" coq-version-parts}";
-in
-
-with coqPackages;
-
-pkgs.stdenv.mkDerivation {
-
-  name = "aac-tactics";
-
-  buildInputs = with coq.ocamlPackages; [ ocaml findlib ]
-    ++ pkgs.lib.optionals shell [ merlin ocp-indent ocp-index ];
-
-  propagatedBuildInputs = [
-    coq
-  ];
-
-  src = if shell then null else ./.;
-
-  installFlags = "COQMF_COQLIB=$(out)/lib/coq/${coq.coq-version}/";
-}
+{ config ? {}, withEmacs ? false, print-env ? false, do-nothing ? false,
+  update-nixpkgs ? false, ci-matrix ? false,
+  override ? {}, ocaml-override ? {}, global-override ? {},
+  bundle ? null, job ? null, inNixShell ? null, src ? ./.,
+}@args:
+let auto = fetchGit {
+  url = "https://github.com/coq-community/coq-nix-toolbox.git";
+  ref = "master";
+  rev = import ./.nix/coq-nix-toolbox.nix;
+}; in
+(import auto ({inherit src;} // args))

meta.yml

@@ -53,12 +53,20 @@ supported_ocaml_versions:
     text: 4.05.0 or later
     opam: '{>= "4.05.0"}'
 
-tested_coq_nix_versions:
-- version_or_url: https://github.com/coq/coq-on-cachix/tarball/master
-
 tested_coq_opam_versions:
 - version: dev
 
+cachix:
+- name: coq
+- name: coq-community
+  token: CACHIX_AUTH_TOKEN
+
+nix-bundles:
+- bundle: default
+  packages:
+  - name: coq
+    version: master
+
 namespace: AAC_tactics
 
 keywords: