diff --git a/.azure/linux-stack.bashrc b/.azure/linux-stack.bashrc
deleted file mode 100644
index 61f790fa8..000000000
--- a/.azure/linux-stack.bashrc
+++ /dev/null
@@ -1 +0,0 @@
-export PATH=$HOME/.local/bin:$PATH
diff --git a/.azure/linux-stack.yml b/.azure/linux-stack.yml
deleted file mode 100644
index aad4722ef..000000000
--- a/.azure/linux-stack.yml
+++ /dev/null
@@ -1,76 +0,0 @@
-jobs:
-- job: Linux_Stack
-  timeoutInMinutes: 0
-  pool:
-    vmImage: ubuntu-16.04
-  strategy:
-    matrix:
-      stack-8.8.2:
-        YAML_FILE: stack-8.8.2.yaml
-      stack-8.8.1:
-        YAML_FILE: stack-8.8.1.yaml
-      stack-8.6.5:
-        YAML_FILE: stack-8.6.5.yaml
-      stack-8.6.4:
-        YAML_FILE: stack-8.6.4.yaml
-      stack-8.4.4:
-        YAML_FILE: stack-8.4.4.yaml
-      stack-8.4.3:
-        YAML_FILE: stack-8.4.3.yaml
-      stack-8.4.2:
-        YAML_FILE: stack-8.4.2.yaml
-      stack-8.2.2:
-        YAML_FILE: stack-8.2.2.yaml
-  variables:
-    STACK_ROOT: /home/vsts/.stack
-  steps:
-  - task: Cache@2
-    inputs:
-      key: '"stack" | "$(Agent.OS)" | $(Build.SourcesDirectory)/$(YAML_FILE)'
-      path: .azure-cache
-      cacheHitVar: CACHE_RESTORED
-    displayName: "Download cache"
-  - bash: |
-      mkdir -p $STACK_ROOT
-      tar -vxzf .azure-cache/stack-root.tar.gz -C /
-      mkdir -p .stack-work
-      tar -vxzf .azure-cache/stack-work.tar.gz
-    displayName: "Unpack cache"
-    condition: eq(variables.CACHE_RESTORED, 'true')
-  - bash: |
-      git submodule sync
-      git submodule update --init
-  - bash: |
-      mkdir -p ~/.local/bin
-      curl -L https://get.haskellstack.org/stable/linux-x86_64.tar.gz | \
-        tar vxz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'
-    displayName: Install stack
-  - bash: |
-      source .azure/linux-stack.bashrc
-      stack setup --stack-yaml $(YAML_FILE)
-    displayName: Install GHC
-  - bash: |
-      source .azure/linux-stack.bashrc
-      stack  --stack-yaml $(YAML_FILE) --install-ghc build --only-dependencies
-    displayName: Build dependencies
-  - bash: |
-      source .azure/linux-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE)
-    displayName: Build `haskell-lsp`
-  - bash: |
-      source .azure/linux-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE) --flag haskell-lsp:demo
-    displayName: Build language server example
-  - bash: |
-      source .azure/linux-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE) --test --bench --only-dependencies
-    displayName: Build Test-dependencies
-  - bash: |
-      source .azure/linux-stack.bashrc
-      stack test --stack-yaml $(YAML_FILE) --dump-logs
-    displayName: "Run Tests"
-  - bash: |
-      mkdir -p .azure-cache
-      tar -vczf .azure-cache/stack-root.tar.gz $STACK_ROOT
-      tar -vczf .azure-cache/stack-work.tar.gz .stack-work
-    displayName: "Pack cache"
diff --git a/.azure/macos-stack.bashrc b/.azure/macos-stack.bashrc
deleted file mode 100644
index 61f790fa8..000000000
--- a/.azure/macos-stack.bashrc
+++ /dev/null
@@ -1 +0,0 @@
-export PATH=$HOME/.local/bin:$PATH
diff --git a/.azure/macos-stack.yml b/.azure/macos-stack.yml
deleted file mode 100644
index 22a66c466..000000000
--- a/.azure/macos-stack.yml
+++ /dev/null
@@ -1,77 +0,0 @@
-jobs:
-- job: MacOs_Stack
-  timeoutInMinutes: 0
-  pool:
-    vmImage: macOS-10.14
-  strategy:
-    matrix:
-      stack-8.8.2:
-        YAML_FILE: stack-8.8.2.yaml
-      stack-8.8.1:
-        YAML_FILE: stack-8.8.1.yaml
-      stack-8.6.5:
-        YAML_FILE: stack-8.6.5.yaml
-      stack-8.6.4:
-        YAML_FILE: stack-8.6.4.yaml
-      stack-8.4.4:
-        YAML_FILE: stack-8.4.4.yaml
-      stack-8.4.3:
-        YAML_FILE: stack-8.4.3.yaml
-      stack-8.4.2:
-        YAML_FILE: stack-8.4.2.yaml
-      stack-8.2.2:
-        YAML_FILE: stack-8.2.2.yaml
-  variables:
-    STACK_ROOT: $(Build.SourcesDirectory)/.stack
-  steps:
-  - task: Cache@2
-    inputs:
-      key: '"stack" | "$(Agent.OS)" | $(Build.SourcesDirectory)/$(YAML_FILE)'
-      path: .azure-cache
-      cacheHitVar: CACHE_RESTORED
-    displayName: "Download cache"
-  - bash: |
-      mkdir -p $STACK_ROOT
-      tar -vxzf .azure-cache/stack-root.tar.gz -C /
-      mkdir -p .stack-work
-      tar -vxzf .azure-cache/stack-work.tar.gz
-    displayName: "Unpack cache"
-    condition: eq(variables.CACHE_RESTORED, 'true')
-  - bash: |
-      git submodule sync
-      git submodule update --init
-    displayName: Sync submodules
-  - bash: |
-      mkdir -p ~/.local/bin
-      curl -skL https://get.haskellstack.org/stable/osx-x86_64.tar.gz | \
-        tar vxz --strip-components=1 --include '*/stack' -C ~/.local/bin;
-    displayName: Install stack
-  - bash: |
-      source .azure/macos-stack.bashrc
-      stack setup --stack-yaml $(YAML_FILE)
-    displayName: Install GHC
-  - bash: |
-      source .azure/macos-stack.bashrc
-      stack --stack-yaml $(YAML_FILE) --install-ghc build --only-dependencies
-    displayName: Build dependencies
-  - bash: |
-      source .azure/macos-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE)
-    displayName: Build `haskell-lsp`
-  - bash: |
-      source .azure/macos-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE) --flag haskell-lsp:demo
-    displayName: Build language server example
-  - bash: |
-      source .azure/macos-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE) --test --bench --only-dependencies
-    displayName: Build Test-dependencies
-  - bash: |
-      source .azure/macos-stack.bashrc
-      stack test --stack-yaml $(YAML_FILE) --dump-logs
-    displayName: "Run Tests"
-  - bash: |
-      mkdir -p .azure-cache
-      tar -vczf .azure-cache/stack-root.tar.gz $STACK_ROOT
-      tar -vczf .azure-cache/stack-work.tar.gz .stack-work
-    displayName: "Pack cache"
diff --git a/.azure/windows-stack.bashrc b/.azure/windows-stack.bashrc
deleted file mode 100644
index f29288d14..000000000
--- a/.azure/windows-stack.bashrc
+++ /dev/null
@@ -1,2 +0,0 @@
-export LOCAL_BIN_PATH=$(cygpath $APPDATA\\local\\bin)
-export PATH=$LOCAL_BIN_PATH:$PATH
diff --git a/.azure/windows-stack.yml b/.azure/windows-stack.yml
deleted file mode 100644
index 028182974..000000000
--- a/.azure/windows-stack.yml
+++ /dev/null
@@ -1,78 +0,0 @@
-jobs:
-- job: Windows_Stack
-  timeoutInMinutes: 0
-  pool:
-    vmImage: windows-2019
-  strategy:
-    matrix:
-      stack-8.8.2:
-        YAML_FILE: stack-8.8.2.yaml
-      stack-8.8.1:
-        YAML_FILE: stack-8.8.1.yaml
-      stack-8.6.5:
-        YAML_FILE: stack-8.6.5.yaml
-      stack-8.6.4:
-        YAML_FILE: stack-8.6.4.yaml
-      stack-8.4.4:
-        YAML_FILE: stack-8.4.4.yaml
-      stack-8.4.3:
-        YAML_FILE: stack-8.4.3.yaml
-      stack-8.4.2:
-        YAML_FILE: stack-8.4.2.yaml
-      stack-8.2.2:
-        YAML_FILE: stack-8.2.2.yaml
-  variables:
-    STACK_ROOT: "C:\\sr"
-
-  steps:
-  - task: Cache@2
-    inputs:
-      key: '"stack" | "$(Agent.OS)" | $(Build.SourcesDirectory)/$(YAML_FILE)'
-      path: .azure-cache
-      cacheHitVar: CACHE_RESTORED
-    displayName: "Cache stack-root"
-  - bash: |
-      mkdir -p $STACK_ROOT
-      tar -vxzf .azure-cache/stack-root.tar.gz -C /c
-      mkdir -p .stack-work
-      tar -vxzf .azure-cache/stack-work.tar.gz
-    displayName: "Unpack cache"
-    condition: eq(variables.CACHE_RESTORED, 'true')
-  - bash: |
-      git submodule sync
-      git submodule update --init
-    displayName: Sync submodules
-  - bash: |
-      curl -sSkL http://www.stackage.org/stack/windows-x86_64 -o /usr/bin/stack.zip
-      unzip -o /usr/bin/stack.zip -d /usr/bin/
-      mkdir -p "$STACK_ROOT"
-    displayName: Install stack
-  - bash: |
-      source .azure/windows-stack.bashrc
-      stack setup --stack-yaml $(YAML_FILE)
-    displayName: Install GHC
-  - bash: |
-      source .azure/windows-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE) --only-dependencies
-    displayName: Build dependencies
-  - bash: |
-      source .azure/windows-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE)
-    displayName: Build `haskell-lsp`
-  - bash: |
-      source .azure/windows-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE) --flag haskell-lsp:demo
-    displayName: Build language server example
-  - bash: |
-      source .azure/windows-stack.bashrc
-      stack build --stack-yaml $(YAML_FILE) --test --bench --only-dependencies
-    displayName: Build Test-dependencies
-  - bash: |
-      source .azure/windows-stack.bashrc
-      stack test --stack-yaml $(YAML_FILE) --dump-logs
-    displayName: "Run Tests"
-  - bash: |
-      mkdir -p .azure-cache
-      tar -vczf .azure-cache/stack-root.tar.gz $(cygpath $STACK_ROOT)
-      tar -vczf .azure-cache/stack-work.tar.gz .stack-work
-    displayName: "Pack cache"
diff --git a/.github/workflows/haskell.yml b/.github/workflows/haskell.yml
index b1d945b4f..2357515fa 100644
--- a/.github/workflows/haskell.yml
+++ b/.github/workflows/haskell.yml
@@ -1,6 +1,11 @@
 name: Haskell CI
 
-on: [push, pull_request]
+on: 
+  push:
+    branches:
+      - master
+  pull_request:
+
 jobs:
   build:
 
@@ -9,27 +14,20 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ghc: ['9.2.4', '9.0.2', '8.10.7', '8.8.4', '8.6.5']
-        os: [ubuntu-latest, macOS-latest, windows-latest]
-        ospath: [true, false]
-        exclude:
-          # newer 'entropy' doesn't work with old 'unix', and it doesn't have a correct version bound.
-          - ospath: true
-            ghc: 8.6.5
-          # "cabal build" always timeout
-          - ospath: true
-            ghc: 8.8.4
-            os: windows-latest
+        ghc: ['9.4.3', '9.2.5', '9.0.2', '8.10.7']
+        # Unlikely that we'll succeed on windows and fail on macos,
+        # including it is just burning CI time. But windows could have
+        # path or IO issues, so worth including
+        os: [ubuntu-latest, windows-latest]
 
     steps:
-    - uses: actions/checkout@v2
-    - uses: haskell/actions/setup@v1
+    - uses: actions/checkout@v3
+    - uses: haskell/actions/setup@v2
       with:
         ghc-version: ${{ matrix.ghc }}
-        cabal-version: '3.6'
 
     - name: Cabal cache
-      uses: actions/cache@v1
+      uses: actions/cache@v3
       env:
         cache-name: cache-cabal
       with:
@@ -38,32 +36,12 @@ jobs:
         restore-keys: |
           ${{ runner.os }}-build-${{ env.cache-name }}-
 
-    - name: Stack cache
-      uses: actions/cache@v1
-      env:
-        cache-name: cache-stack
-      with:
-        path: ~/.stack
-        key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/*.cabal') }}-${{ hashFiles('**/stack.yaml') }}
-        restore-keys: |
-          ${{ runner.os }}-build-${{ env.cache-name }}-
-
     - name: Cabal update
       run: cabal update
-    - name: Cabal configure
-      shell: bash
-      run: |
-        if [ ${{ matrix.ospath }} = "true" ]; then
-          cabal configure --flags="force-ospath"
-        fi
     - name: Build using cabal
       run: cabal build all
     - name: Test
       run: cabal test all
-    # stack build uses stack.yaml which actually uses ghc-8.10.7
-    - if: matrix.ghc == '8.10.7' && runner.os == 'Linux'
-      name: Build using stack
-      run: stack build
 
   haskell_post_job:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/nix.yaml b/.github/workflows/nix.yaml
index 94a394e42..1e10e5b5f 100644
--- a/.github/workflows/nix.yaml
+++ b/.github/workflows/nix.yaml
@@ -1,6 +1,10 @@
 name: Nix
 
-on: [push, pull_request]
+on: 
+  push:
+    branches:
+      - master
+  pull_request:
 
 jobs:
   nix:
@@ -12,10 +16,10 @@ jobs:
         os: [ubuntu-latest, macOS-latest]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
         with:
           submodules: true
-      - uses: cachix/install-nix-action@v16
+      - uses: cachix/install-nix-action@v18
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - run: nix-shell --run "cabal update && cabal build all"
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
deleted file mode 100644
index 6ab491a34..000000000
--- a/azure-pipelines.yml
+++ /dev/null
@@ -1,31 +0,0 @@
-# Build master, branches starting with `azure` and tags commits
-trigger:
-  branches:
-    include:
-      - master
-      - azure*
-  tags:
-    include:
-      - '*'
-  paths:
-    exclude:
-      - .circleci
-      - LICENSE
-      - '*.md'
-
-# Enable PR triggers that target the master branch
-pr:
-  autoCancel: true # cancel previous builds on push
-  branches:
-    include:
-      - master
-  paths:
-    exclude:
-      - .circleci
-      - LICENSE
-      - '*.md'
-
-jobs:
-- template: ./.azure/linux-stack.yml
-- template: ./.azure/windows-stack.yml
-- template: ./.azure/macos-stack.yml
diff --git a/cabal.project b/cabal.project
index 37b5d32fa..4ffb13028 100644
--- a/cabal.project
+++ b/cabal.project
@@ -6,7 +6,7 @@ packages:
 package lsp
   flags: +demo
 
-index-state: 2022-08-25T22:25:05Z
+index-state: 2023-01-01T00:00:00Z
 
 tests: True
 benchmarks: True
diff --git a/nix/sources.json b/nix/sources.json
index 55059fb80..50e880372 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -5,10 +5,10 @@
         "homepage": "",
         "owner": "hercules-ci",
         "repo": "gitignore.nix",
-        "rev": "5b9e0ff9d3b551234b4f3eb3983744fa354b17f1",
-        "sha256": "01l4phiqgw9xgaxr6jr456qmww6kzghqrnbc7aiiww3h6db5vw53",
+        "rev": "a20de23b925fd8264fd7fad6454652e142fd7f73",
+        "sha256": "07vg2i9va38zbld9abs9lzqblz193vc5wvqd6h7amkmwf66ljcgh",
         "type": "tarball",
-        "url": "https://github.com/hercules-ci/gitignore.nix/archive/5b9e0ff9d3b551234b4f3eb3983744fa354b17f1.tar.gz",
+        "url": "https://github.com/hercules-ci/gitignore.nix/archive/a20de23b925fd8264fd7fad6454652e142fd7f73.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "niv": {
@@ -17,10 +17,10 @@
         "homepage": "https://github.com/nmattia/niv",
         "owner": "nmattia",
         "repo": "niv",
-        "rev": "5830a4dd348d77e39a0f3c4c762ff2663b602d4c",
-        "sha256": "1d3lsrqvci4qz2hwjrcnd8h5vfkg8aypq3sjd4g3izbc8frwz5sm",
+        "rev": "689d0e5539eddd0b0f566aee7bb18629eee7df74",
+        "sha256": "1rld3lk42l6b01f2gcrhq8qm9vry1awmfl29zmpiqda9dy89vbx0",
         "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/5830a4dd348d77e39a0f3c4c762ff2663b602d4c.tar.gz",
+        "url": "https://github.com/nmattia/niv/archive/689d0e5539eddd0b0f566aee7bb18629eee7df74.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs": {
@@ -29,10 +29,10 @@
         "homepage": "",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "5efc8ca954272c4376ac929f4c5ffefcc20551d5",
-        "sha256": "15xncc1afq8v78acrcv8xbfkd3ii147mv9a55823pdbqffzg0x54",
+        "rev": "293a28df6d7ff3dec1e61e37cc4ee6e6c0fb0847",
+        "sha256": "1m6smzjz3agkyc6dm83ffd8zr744m6jpjmffppvcdngk82mf3s3r",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/5efc8ca954272c4376ac929f4c5ffefcc20551d5.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/293a28df6d7ff3dec1e61e37cc4ee6e6c0fb0847.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }
diff --git a/nix/sources.nix b/nix/sources.nix
index 1938409dd..9a01c8acf 100644
--- a/nix/sources.nix
+++ b/nix/sources.nix
@@ -31,8 +31,28 @@ let
           if spec ? branch then "refs/heads/${spec.branch}" else
             if spec ? tag then "refs/tags/${spec.tag}" else
               abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
+      submodules = if spec ? submodules then spec.submodules else false;
+      submoduleArg =
+        let
+          nixSupportsSubmodules = builtins.compareVersions builtins.nixVersion "2.4" >= 0;
+          emptyArgWithWarning =
+            if submodules == true
+            then
+              builtins.trace
+                (
+                  "The niv input \"${name}\" uses submodules "
+                  + "but your nix's (${builtins.nixVersion}) builtins.fetchGit "
+                  + "does not support them"
+                )
+                {}
+            else {};
+        in
+          if nixSupportsSubmodules
+          then { inherit submodules; }
+          else emptyArgWithWarning;
     in
-      builtins.fetchGit { url = spec.repo; inherit (spec) rev; inherit ref; };
+      builtins.fetchGit
+        ({ url = spec.repo; inherit (spec) rev; inherit ref; } // submoduleArg);
 
   fetch_local = spec: spec.path;
 
diff --git a/stack.yaml b/stack.yaml
deleted file mode 100644
index 2ca1055ee..000000000
--- a/stack.yaml
+++ /dev/null
@@ -1,14 +0,0 @@
-resolver: lts-18.18 # GHC 8.10.7
-
-packages:
-- ./lsp
-- ./lsp-types
-- ./lsp-test
-
-flags: {}
-extra-package-dbs: []
-nix:
-  packages: [icu]
-extra-deps:
-- text-rope-0.1
-- co-log-core-0.3.1.0