diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index a0f89d1..862b6e4 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -9,6 +9,10 @@ on:
     - cron:  '0 9 * * *'
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   test:
 
@@ -20,7 +24,6 @@ jobs:
     - name: Checkout repository
       uses: actions/checkout@v6
       with:
-        submodules: recursive
         fetch-depth: 0
 
     - name: Install dependencies
@@ -41,8 +44,6 @@ jobs:
 
     - name: Checkout repository
       uses: actions/checkout@v6
-      with:
-        submodules: recursive
 
     - name: Build documentation
       run: |
diff --git a/.gitignore b/.gitignore
index feeaf02..93adc24 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 .DS_Store
+/.local
+/scripts/Pipfile.lock
 .build
 .netrc
 .swiftpm/config/registries.json
diff --git a/.gitmodules b/.gitmodules
deleted file mode 100644
index 73445c4..0000000
--- a/.gitmodules
+++ /dev/null
@@ -1,3 +0,0 @@
-[submodule "scripts/changes"]
-	path = scripts/changes
-	url = https://github.com/jbmorley/changes.git
diff --git a/scripts/Pipfile b/scripts/Pipfile
new file mode 100644
index 0000000..70010d7
--- /dev/null
+++ b/scripts/Pipfile
@@ -0,0 +1,13 @@
+[[source]]
+
+name = "pypi"
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+
+[packages]
+
+changes-semver = "==6.*"
+
+[requires]
+
+python_version = "3.12"
diff --git a/scripts/changes b/scripts/changes
deleted file mode 160000
index 12a6b90..0000000
--- a/scripts/changes
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 12a6b90b2e9699970b199d622437c7fd0b6b81dd
diff --git a/scripts/environment.sh b/scripts/environment.sh
index 35660c3..ebd0367 100755
--- a/scripts/environment.sh
+++ b/scripts/environment.sh
@@ -25,12 +25,17 @@ SCRIPTS_DIRECTORY="$ROOT_DIRECTORY/scripts"
 
 export LOCAL_TOOLS_PATH="$ROOT_DIRECTORY/.local"
 
-export BIN_DIRECTORY="$ROOT_DIRECTORY/.local/bin"
-export PATH=$BIN_DIRECTORY:$PATH
+# Keep Python user installs local to the project instead of polluting the host.
+export PYTHONUSERBASE="$LOCAL_TOOLS_PATH/python"
+mkdir -p "$PYTHONUSERBASE"
+export PATH="$PYTHONUSERBASE/bin":$PATH
 
-source "$LOCAL_TOOLS_PATH/python/bin/activate"
-
-export PIPENV_VENV_IN_PROJECT=1
+# Keep pipenv virtualenvs local and predictable.
+export WORKON_HOME="$LOCAL_TOOLS_PATH"
+export PIPENV_CUSTOM_VENV_NAME="venv"
+export PIPENV_VENV_IN_PROJECT=0
 export PIPENV_IGNORE_VIRTUALENVS=1
+export PIPENV_PIPFILE="$SCRIPTS_DIRECTORY/Pipfile"
 
-export PATH=$PATH:"$SCRIPTS_DIRECTORY/changes"
+# Add the tools to the path.
+export PATH="$LOCAL_TOOLS_PATH/venv/bin":$PATH
diff --git a/scripts/gh-release.sh b/scripts/gh-release.sh
new file mode 100755
index 0000000..5c956d5
--- /dev/null
+++ b/scripts/gh-release.sh
@@ -0,0 +1,34 @@
+#!/bin/bash
+
+# Copyright (c) 2022-2026 Jason Morley
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+set -e
+set -o pipefail
+set -x
+
+# Actually make the release.
+gh release create "$CHANGES_TAG" --title "$CHANGES_QUALIFIED_TITLE" --notes-file "$CHANGES_NOTES_FILE"
+
+# Upload the attachments.
+for attachment in "$@"
+do
+    gh release upload "$CHANGES_TAG" "$attachment"
+done
diff --git a/scripts/install-dependencies.sh b/scripts/install-dependencies.sh
index db66820..f3945c3 100755
--- a/scripts/install-dependencies.sh
+++ b/scripts/install-dependencies.sh
@@ -29,8 +29,6 @@ ROOT_DIRECTORY="$( cd "$( dirname "$( dirname "${BASH_SOURCE[0]}" )" )" &> /dev/
 SCRIPTS_DIRECTORY="$ROOT_DIRECTORY/scripts"
 
 LOCAL_TOOLS_PATH="$ROOT_DIRECTORY/.local"
-CHANGES_DIRECTORY="$SCRIPTS_DIRECTORY/changes"
-BUILD_TOOLS_DIRECTORY="$SCRIPTS_DIRECTORY/build-tools"
 
 # Install tools defined in `.tool-versions`.
 cd "$ROOT_DIRECTORY"
@@ -42,12 +40,9 @@ if [ -d "$LOCAL_TOOLS_PATH" ] ; then
 fi
 mkdir -p "$LOCAL_TOOLS_PATH"
 
-# Set up a Python venv to bootstrap our python dependency on `pipenv`.
-python -m venv "$LOCAL_TOOLS_PATH/python"
-
 # Source `environment.sh` to ensure the remainder of our paths are set up correctly.
 source "$SCRIPTS_DIRECTORY/environment.sh"
 
-# Install the Python dependencies.
-pip install --upgrade pip pipenv wheel certifi
-PIPENV_PIPFILE="$CHANGES_DIRECTORY/Pipfile" pipenv install
+# Install the Python dependencies (uses PIPENV_PIPFILE from environment.sh).
+pip install --user --ignore-installed --upgrade pip pipenv wheel certifi
+pipenv install
diff --git a/scripts/release.sh b/scripts/release.sh
index 3d027f2..bd725f5 100755
--- a/scripts/release.sh
+++ b/scripts/release.sh
@@ -22,9 +22,7 @@
 
 SCRIPTS_DIRECTORY="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 ROOT_DIRECTORY="${SCRIPTS_DIRECTORY}/.."
-CHANGES_DIRECTORY="${SCRIPTS_DIRECTORY}/changes"
-CHANGES_SCRIPT="${CHANGES_DIRECTORY}/changes"
-RELEASE_SCRIPT="${CHANGES_DIRECTORY}/examples/gh-release.sh"
+RELEASE_SCRIPT="${SCRIPTS_DIRECTORY}/gh-release.sh"
 
 source "${SCRIPTS_DIRECTORY}/environment.sh"