[tlbuild] Problems with building texlive/context from its sources

[Jakob Jakobson]

Dear developers,

I am/become one of the texlive mantainers for its flatpak package, a 
more or less recent and new approach for establishing a linux packaging 
format. The flatpak packages are usually build from source and so is the 
texlive package. You can find it under 
https://github.com/flathub/org.freedesktop.Sdk.Extension.texlive/tree/branch/22.08 
. The file 
https://github.com/flathub/org.freedesktop.Sdk.Extension.texlive/blob/branch/22.08/org.freedesktop.Sdk.Extension.texlive.yml 
is the build manifest which lists the files and commands/additional 
steps needed for the build process.
The current build of texlive works well with pdflatex/lualatex/xelatex 
but with the context part I have some problems. Therefore, I would 
appreciate any help with the following questions:
1) Is context included in the texlive-20230313* tarballs or do I have to 
download it in an extra step?
2) If context is included in the texlive-20230313* tarballs, do I have 
to additionally download luametatex or is luametatex a part of context?
3) If luametatex is via context in the texlive-20230313* tarballs, how 
do I build it?

Sorry for those (perhaps obvious) questions but I have to admit that I 
find the texlive building process quite confusing. Also, I could not 
find any installation guide that covers the scenario of building context 
within a texlive 2023 installation from its sources on linux.

Thanks in advance and regards
Jakob