Project Overte builder

Builds Overte (codename "Project Athena"), an open source Interface and Server solution for virtual worlds.

Supported platforms

• CentOS 8.x (see notes below)
• Debian 10 (codename Buster)
  • Linux Mint Debian Edition 4
• Debian 11 (codename Bulleye, can use system Qt)
• Debian 12 (codename Bookwork, can use system Qt)
• Fedora 31 (end of life)
• Fedora 32 (end of life)
• Fedora 33 (end of life, can use system Qt)
• Fedora 34 (end of life, can use system Qt)
• Fedora 35 (can use system Qt)
• Manjaro (can use system Qt)
  • Manjaro ARM
• Ubuntu 18.04.x (codename Bionic, has pre-built Qt). See note below.
  • Linux Mint 19.x
• Ubuntu 20.04.x (codename Focal)
  • Linux Mint 20.x
• Ubuntu 21.04 (end of life, codename Hirsute, can use system Qt)
• Ubuntu 21.10 (end of life, codename Impish, can use system Qt)
• OpenSuSE Tumbleweed
• (more coming soon)

Notes on CentOS / RHEL 8.x builds

Before starting the build

• Enable PowerTools and EPEL repos dnf install epel-release dnf config-manager --set-enabled PowerTools

• Make sure basic dev tools are installed dnf groupinstall "Development Tools" "RPM Development Tools"

• CentOS/RHEL has two Python version, make sure Python 2 is default dnf install python2 python36 alternatives --set python /usr/bin/python2

Notes on Ubuntu 18.04

Overte requires OpenSSL 1.1 at the very least, but installing libssl-dev conflicts with installing npm. Therefore the system npm package can't be used, and isn't listed as a dependency. As a result, jsdoc can't be generated, and tab completion in the JS console won't work.

It's possible to install npm from an outside source, and the build process should find it and use it in that case.

Notes on Amazon Linux 2

Amazon Linux is a very trimmed-down distribution that lacks some packages that are present in other distributions. Unfortunately it even lacks Perl by default, which means overte-builder can't run on a default installation.

To deal with this issue, run the install_amazon_linux_deps.sh script before running overte-builder.

Unsupported platforms

• Amazon Linux 2

Currently unsupported due to it's outdated and tiny package base.

Instructions:

You can see the possible environment variables for building here.

git clone https://github.com/overte-org/overte-builder.git
cd overte-builder
chmod +x overte-builder
./overte-builder

What it does

• Installs all required packages
• Downloads the Overte source from github
• Downloads and compiles Qt if required
• Compiles the Overte source
• Creates a wrapper script to make it run correctly
• Creates a desktop icon
• Adds it to the menu

It will ask some questions, all of which can be left with their default values.

It will detect the system's core count and amount of available memory, and do a parallel build taking care not to exhaust the system memory on high core count systems.

Build targets

The script by default builds the GUI ('interface') but it can also build the server components using the --build option. For instance:

$ ./overte-builder --build server

Will build only the server components. To build both, separate entries with a comma:

$ ./overte-builder --build server,client

Have in mind that each build overwrites the previous one, so if you want to have both desktop and server components at the same time, you need to build them both in one command like above.

Building AppImages

You can create an AppImage using the --make-appimage argument.

When making an AppImage, you will want to create it on the oldest possible distribution in order to achieve the greatest compatibility. You will want to also ensure that your distribution is fully up to date. For example, on Ubuntu you will want to run sudo apt-get update && sudo apt-get upgrade prior to building.

Qt

The Overte codebase uses a specific version of Qt. Binary packages are only available for some platforms. For platforms without a package, Qt can be built from source by the script.

WARNING: The Qt build uses a large amount of RAM, which can be a problem with VPSes. A minimum of 4 GB RAM + 2GB swap is recommended for building Qt with one process. The swap usage should be tolerable, as Qt has a few very memory intensive parts in the compilation process, but the rest is much less so.

In case of trouble, look at the autodetected number of cores, eg:

Checking how many cores to use for building Overte... 4 cores, memory limited to 2
Checking how many cores to use for building Qt... 4 cores, memory limited to 3

And manually specify a lower number. For instance:

./overte-builder --qt-cores 1

In any case, building in low resource environments is slow and problematic. While it can be done, it might be faster and easier to do the build in Docker or a bigger VM running on a local machine, and then copy the files over.

Adding support for more distributions

The script is intended to be as automatic as possible, and to set it all up for the user. For that to work, it depends on including a list of dependencies inside the script itself, but it can work without that as well. Here's how:

First, get a list of the supported distributions, and find the closest one:

$ ./overte-builder --get-supported
ubuntu-19.10
linuxmint-19.3
custom
fedora-31
ubuntu-16.04
ubuntu-18.04

Tell the script to dump the list of dependencies for that distro:

$ ./overte-builder --get-source-deps ubuntu-18.04
...
$ ./overte-builder --get-qt-deps ubuntu-18.04
...

Use those results as a starting point. Choosing a similar distribution (eg, 18.04 when running on 18.10) should mostly work, and only a few package names might need fixing. With the package list figured out, install them:

$ sudo apt-get install ...

After installing the packages, you can try the script by selecting the special distro name "custom", which will perform a build without any hardcoded dependency checking:

$ ./overte-builder --distro custom

After that, the build process should begin. If there are problems, it's likely more packages need to be installed.

Once you know what packages are needed, a new configuration can be created. Configurations are stored in the distros subdirectory. Copy the one you used as a base, and make your modifications. The syntax for the file is that of a Perl script.

Once modifications are done, you can use the maint script to clean it up:

$ ./maint --cleanup distros/new-distro.cfg

This will verify that your config file parses correctly, will apply a standard indentation and order the contents. This makes it easier to see what changed between different releases of a distribution, and makes for better patches.

Questions

How much disk space does it need?

Some packages will likely need to be installed, depending on the distro and the current instalation. On a Fedora 31 VPS without a desktop, this required 130 MiB of packages.

In addition to any packages that may be needed to do the build:

• About 20 GiB for a full build including Qt.
• About 10 GiB if the binary Qt package is used.
• About 8.2 GiB after deleting downloaded source files.

How long does it take?

It's extremely variable, depending greatly on hardware. Here are some sample numbers, only of the compilation process:

Processor	Qt	CMake	Vircadia Client	Vircadia Server
Ryzen 9 3950X, using 32 cores	19:01	?	4:07	?
Ryzen 9 3950X, using 16 cores in VM	25:32	?	4:46	?
Core i7-8550U (Dell XPS 13 laptop)	2:20:22	?	19:37	?
Linode 8GB	3:09:40	14:25	31:47	16:30

Why is it using such a weird number of cores for the build?

The script measures available (not total) RAM, and estimates a requirement of 1 GiB needed per build process. So if you have 8 GiB RAM free, you'll get a maximum of 8 cores used for the build.

The script is intended to be friendly and not kill the user's machine through memory exhaustion, so it's intentionally very conservative. You can specify a higher numer if you wish.

Contact

For questions and support, contact Dale Glass#8576 on Discord.