Use Docker for our build env

I think this will be a benefit overall, it gives us a reproducible build
environment that can be used in or outside of GitHub Actions.

Also, it will let us build in versions of Ubuntu/Debian other than what
GitHub Actions supports for runners, and possibly even other
architectures with Qemu.

.github/workflows/build.yml

@@ -22,21 +22,34 @@ jobs:
       matrix:
         ubuntu_version: ["22.04", "24.04", "24.10"]
     runs-on: ubuntu-latest
-    container:
-      image: ubuntu:${{ matrix.ubuntu_version }}
     steps:
+        # See the docs: https://github.com/docker/build-push-action
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+        # This action checks out the source as part of the action and can therefore
+        # go before the checkout step.
+      - name: Build Docker Image
+        uses: docker/build-push-action@v6
+        with:
+          tags: ghostty-ubuntu:${{ matrix.ubuntu_version }}
+          build-args: |
+            UBUNTU_VERSION=${{ matrix.ubuntu_version }}
+          push: false
+          load: true
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
       - name: Checkout ghostty-ubuntu
         uses: actions/checkout@v4
 
-      - name: Setup Build Env
-        run: ./setup-env.sh
-
       - name: Build Ghostty
-        run: ./build-ghostty.sh
+        run: docker run --rm -v$PWD:/workspace -w /workspace ghostty-ubuntu:${{ matrix.ubuntu_version }} /bin/bash build-ghostty.sh
 
       - name: Lint .deb Package
-        run: lintian ghostty_*.deb || true # Lintian shouldn't fail our build yet
-
+        # Lintian shouldn't fail our build yet
+        run: docker run --rm -v$PWD:/workspace -w /workspace ghostty-ubuntu:${{ matrix.ubuntu_version }} lintian ghostty_*.deb || true 
+
       - name: Upload Artifact
         uses: actions/upload-artifact@v4
         with:

Dockerfile

@@ -0,0 +1,34 @@
+ARG UBUNTU_VERSION="24.10"
+FROM ubuntu:${UBUNTU_VERSION}
+
+# Install Build Tools
+RUN DEBIAN_FRONTEND="noninteractive" apt-get -qq update && \
+    apt-get -qq -y install \
+    build-essential \
+    libbz2-dev \
+    libonig-dev \
+    lintian \
+    lsb-release \
+    pandoc \
+    wget
+
+# Install Minisign
+# https://jedisct1.github.io/minisign/
+RUN wget -q "https://github.com/jedisct1/minisign/releases/download/0.11/minisign-0.11-linux.tar.gz" && \
+    tar -xzf minisign-0.11-linux.tar.gz && \
+    mv minisign-linux/x86_64/minisign /usr/local/bin && \
+    rm -r minisign-linux
+
+# Install zig
+# https://ziglang.org/download/
+ARG ZIG_VERSION="0.13.0"
+RUN wget -q "https://ziglang.org/download/$ZIG_VERSION/zig-linux-x86_64-$ZIG_VERSION.tar.xz" && \
+    tar -xf "zig-linux-x86_64-$ZIG_VERSION.tar.xz" -C /opt && \
+    rm "zig-linux-x86_64-$ZIG_VERSION.tar.xz" && \
+    ln -s "/opt/zig-linux-x86_64-$ZIG_VERSION/zig" /usr/local/bin/zig
+
+# Install Ghostty Dependencies
+RUN DEBIAN_FRONTEND="noninteractive" apt-get -qq update && \
+    apt-get -qq -y install \
+    libadwaita-1-dev \
+    libgtk-4-dev

build-ghostty.sh

@@ -10,7 +10,6 @@ UBUNTU_DIST=$(lsb_release -sc)
 #FULL_VERSION="$GHOSTTY_VERSION-0~${UBUNTU_DIST}1"
 FULL_VERSION="$GHOSTTY_VERSION-0~ppa3"
 
-
 # Fetch Ghostty Source
 wget -q "https://release.files.ghostty.org/$GHOSTTY_VERSION/ghostty-$GHOSTTY_VERSION.tar.gz"
 wget -q "https://release.files.ghostty.org/$GHOSTTY_VERSION/ghostty-$GHOSTTY_VERSION.tar.gz.minisig"