+# vim:ft=Dockerfile
+FROM debian:sid
+
+RUN echo force-unsafe-io > /etc/dpkg/dpkg.cfg.d/docker-apt-speedup
+# Paper over occasional network flakiness of some mirrors.
+RUN echo 'APT::Acquire::Retries "5";' > /etc/apt/apt.conf.d/80retry
+
+# NOTE: I tried exclusively using gce_debian_mirror.storage.googleapis.com
+# instead of httpredir.debian.org, but the results (Fetched 123 MB in 36s (3357
+# kB/s)) are not any better than httpredir.debian.org (Fetched 123 MB in 34s
+# (3608 kB/s)). Hence, let’s stick with httpredir.debian.org (default) for now.
+
+# Install mk-build-deps (for installing the i3 build dependencies),
+# clang and clang-format-3.8 (for checking formatting and building with clang),
+# lintian (for checking spelling errors),
+# test suite dependencies (for running tests)
+RUN apt-get update && \
+ DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+ build-essential clang git autoconf automake libxcb-randr0-dev pkg-config libpam0g-dev \
+ libcairo2-dev libxcb1-dev libxcb-dpms0-dev libxcb-image0-dev libxcb-util0-dev \
+ libxcb-xrm-dev libev-dev libxcb-xinerama0-dev libxcb-xkb-dev libxkbcommon-dev \
+ libxkbcommon-x11-dev && \
+ rm -rf /var/lib/apt/lists/*
+
+WORKDIR /usr/src