As of today it's a nightmare to understands how things goes between tuleap sources and https://github.com/Enalean/docker-tuleap-aio-dev/
Basically:
sequenceDiagram
participant T as Tuleap
participant D as enalean/tuleap-aio-dev
T->>D: docker-compose up -d web
D->>D: systemd init with "run-dev.service"
D->>D: run-dev.service executes image's /root/app/run.sh
D->>T: /root/app/run.sh executes /usr/share/tuleap/.../run_dev/run.sh
T->>D: when completed, /root/app/run.sh execution continues
D->>T: development server is started
When you try to understand how things are started (let say to switch from one version of php to another) it's a major source of headaches.
The github repository should only have what's mandatory to build the docker image but everything else must be in Tuleap sources