Build instructions

[gbraad]

Currently this lacks the build instructions and dependencies. This issue will collect the steps I have performed and the issues I encountered:

Basing on Fedora 24

dnf install -y git make sudo rpm-ostree flatpak
git clone https://github.com/matthiasclasen/flatpak-runtime.git
cd flatpak-runtime
make

[gbraad]

Currently the process fails on rpm-ostree with:

Installing packages: [====================================================================================================================================================================================================================================] 100%
Writing '/var/tmp/rpm-ostree.jeET70/rootfs.tmp/usr/share/rpm-ostree/treefile.json'
Executing postprocessing script 'treecompose-post.sh'
error: While executing postprocessing script 'treecompose-post.sh': Operation not permitted
Makefile:17: recipe for target 'repo/refs/heads/base/org.flatpak.Runtime/x86_64/1' failed

[gbraad]

Same results for Fedora 23, CentOS 7 (wtih atomic.repo). However, a CI runner passes this step: https://gitlab.com/gbraad/flatpak-runtime-build/builds/2781141

Any idea what this could be? I suspected SELinux... but this has been disabled and no difference...