It’s installed separately.
This should fix the failing travis build.
# Install i3 build dependencies.
COPY debian/control /usr/src/i3-debian-packaging/control
RUN linux32 apt-get update && \
+ sed -i '/^\s*libxcb-xrm-dev/d' /usr/src/i3-debian-packaging/control && \
DEBIAN_FRONTEND=noninteractive mk-build-deps --install --remove --tool 'apt-get --no-install-recommends -y' /usr/src/i3-debian-packaging/control && \
rm -rf /var/lib/apt/lists/*
# Install i3 build dependencies.
COPY debian/control /usr/src/i3-debian-packaging/control
RUN apt-get update && \
+ sed -i '/^\s*libxcb-xrm-dev/d' /usr/src/i3-debian-packaging/control && \
DEBIAN_FRONTEND=noninteractive mk-build-deps --install --remove --tool 'apt-get --no-install-recommends -y' /usr/src/i3-debian-packaging/control && \
rm -rf /var/lib/apt/lists/*