[Linux] Read this before posting anything

[Shepard]

Last updated: December 17th 2022

Before reporting anything that concerns Linux, please read the following statements:

Dedicated server

If you want to setup a ZPS v3.1+ dedicated server on Linux, please read this Steam guide.

Supported distributions

When it comes to Linux, Valve only supports 2 distributions : Ubuntu and SteamOS.

For SteamOS, we can't guarentee ZPS will work at 100% but there are high chances that it will happen. If you use this distribution and make the test yourself, please notify us so we can update this statement.

For Ubuntu, we support the default Desktop/Server flavours and it's variants like xubuntu, kubuntu and lubuntu. We can guarentee a full compatibility on LTS (Long Term Support) versions but latest versions (if available) might cause problems. If you are using an Ubuntu version which is more recent than the latest LTS one and make the test yourself, please notify us so we can update this statement.

That is how Valve supports the Steam client and the Source 2013 engine under Linux. For technical reasons, we have no choice but to follow that way as well.

We do NOT support forks (clones) of Ubuntu, this includes Linux Mint, Bodhi Linux and many others. The same applies to forks of Debian and SteamOS.

A warning about other Linux distributions such as ArchLinux, Fedora, Gentoo, CentOS/RedHat and their variants/forks: they might run ZPS out of the box or after a few changes to your system/Steam/ZPS installation(s). But we (the development and Linux playtesting teams) have NOT tested them and we do NOT support them. The "Source SDK 2013 Multiplayer" would be a great starting point to test your Linux distribution if it could potentially run ZPS.

"Could not load library client" error

Since ZPS v3.1.1, we shipped a compiled version of OpenSSL that is known to work with ZPS. To prevent breaking existing working setups, that shipped version of OpenSSL is not used by default. If you want to use it, add the "-linux-extra-bins" parameter in the command-line launch options (right-click on ZPS in Steam --> Properties --> Set advanced launch options). If that does not work, you can keep reading this section.

Thanks to Steam community member "Rakkah" for supplying the following information:

If you have the "Could not load library client. Try restarting. If that doesn't work" error when trying to run the game natively without the Steam Runtime, it is because the version of cURL we shipped requires OpenSSL 1.0.1. To check if your version is correct, you can run the following commands in your terminal (assuming ZPS is installed in the default Steam library):

$ cd ~/.local/share/Steam/steamapps/common/Zombie Panic Source
$ ldd ./zps/bin/libcurl.so

If the output is similar to this:

./zps/bin/libcurl.so: /usr/lib/liblber-2.4.so.2: no version information available (required by ./zps/bin/libcurl.so)
./zps/bin/libcurl.so: /usr/lib/libldap_r-2.4.so.2: no version information available (required by ./zps/bin/libcurl.so)
./zps/bin/libcurl.so: /usr/lib/libssl.so.1.0.0: version `OPENSSL_1.0.1' not found (required by ./zps/bin/libcurl.so)
        linux-gate.so.1 (0xf7f99000)
        liblber-2.4.so.2 => /usr/lib/liblber-2.4.so.2 (0xf7e80000)
        libldap_r-2.4.so.2 => /usr/lib/libldap_r-2.4.so.2 (0xf7e23000)
        libpthread.so.0 => /lib/libpthread.so.0 (0xf7e04000)
        libssl.so.1.0.0 => /usr/lib/libssl.so.1.0.0 (0xf7d94000)
        libcrypto.so.1.0.0 => /usr/lib/libcrypto.so.1.0.0 (0xf7b7c000)
        libz.so.1 => /lib/libz.so.1 (0xf7b63000)
        libc.so.6 => /lib/libc.so.6 (0xf7982000)
        libresolv.so.2 => /lib/libresolv.so.2 (0xf796a000)
        libsasl2.so.3 => /usr/lib/libsasl2.so.3 (0xf794a000)
        libssl.so.1.1 => /usr/lib/libssl.so.1.1 (0xf78d9000)
        libcrypto.so.1.1 => /usr/lib/libcrypto.so.1.1 (0xf7669000)
        /lib/ld-linux.so.2 (0xf7f9b000)
        libdl.so.2 => /lib/libdl.so.2 (0xf7662000)

Then you can try to compile OpenSSL 1.0.1 yourself and install it in ZPS:

wget https://github.com/openssl/openssl/archive/OpenSSL_1_0_1u.tar.gz
tar -zxvf OpenSSL_1_0_1u.tar.gz
cd openssl-OpenSSL_1_0_1u
setarch i386 ./config -m32 -shared
make depend
make
cp libcrypto.so.1.0.0 ~/.local/share/Steam/steamapps/common/Zombie\ Panic\ Source/zps/bin
cp libssl.so.1.0.0 ~/.local/share/Steam/steamapps/common/Zombie\ Panic\ Source/zps/bin

Steam Runtime

The "Steam Runtime" is a sandboxed Ubuntu installation that contains most of the libraries/components required by video games shipped on Steam. It is downloaded, installed and used by default unless you (or you distribution) decided otherwise.

Disabling the Steam Runtime might give you performance boosts since Steam, Source 2013 and ZPS will use the libraries installed on your system rather than the one shipped in the Steam Runtime.

However, this could also lead to problems like ZPS no longer starting or Steam's overlay not working or in-game issues.

Like Valve, we only treat issues where the Steam Runtime is enabled. We won't treat issues where the Steam Runtime has been disabled and/or a custom one is used.

We understand that for some people in very specific cases, disabling the Steam Runtime might be the only way to play ZPS properly but there is nothing we can do about that.

Error involving "GCC_7.0.0"

This can be fixed by renaming/moving or deleting the "libgcc_s.so.1" file in the "bin" folder of your ZPS client or dedicated server.

Drivers for the GPU (graphics card)

We test and develop ZPS on Linux with the "free" AMD, Intel, NVIDIA drivers. Using "proprieatary" (also called "non-free") drivers might cause more problems that it solves.

List of known issues

• If you have the"You are in insecure mode. You must restart before you can connect to secure servers." message when joining a server, then Steam isn't passing the required "-secure -steam" arguments properly. You need to add them manually in your launch options.
  
• The GNOME desktop (default on Debian and Ubuntu) might tell you that "zps_linux is not responding" and you have the choice between "Force kill" and "Wait", just press "Wait", the game is not crashed and it's still loading assets.
  
• Some NVIDIA GPUs with Nouveau (the free drivers) might have a problem related to anti-aliasing (AA). It might not work or cause problems in-game such as having a black screen. If this is the case, disabling anti-aliasing might solve the problem.
  
• The main menu might disappear or be shown in a weird way where any interaction is impossible. We are still trying to narrow down the problem and see if we can fix it.