TLDR: Just scroll down to [The solution](https://gist.github.com/thetredev/f200090c4c975a319ea3b9f896964c2f#the-solution).

# The problem
Today (2024-03-09) I tried to run Counter-Strike Source on Void Linux via the Flatpak version of Steam on Void Linux. I have updated all my Flatpaks via `flatpak update` before I started Steam.

After trying to run Counter-Strike Source, it just stopped. No game window opened. The green `Play` button of the game just updated to the blue `Stop` button and eventually reverted back to the green `Play` button.

So I ran Steam via the console using `flatpak run com.valvesoftware.Steam` to look at the logs. The game had problems with line 72 of `hl2.sh`, printing
```
<flatpak game directory>/hl2.sh: line 72: <game PID> Aborted
```

After some googling I stumbled upon this Reddit thread: https://www.reddit.com/r/linux_gaming/comments/18ykfuz/counter_strike_source_wont_launch/

There, the comment from `PM_ME_FLUFFY_SHIBES` was extremely helpful: https://www.reddit.com/r/linux_gaming/comments/18ykfuz/comment/kgejtw3/
> Ah you've been hit with the malloc bug when it comes to source engine games. Install `lib32-libjemalloc` and run the game with
> 
> LD_PRELOAD=$LD_PRELOAD:/usr/lib32/libjemalloc.so.2 %command%
> 
> Check out protondb entries for the game.

# Trying libjemalloc

The package `lib32-libjemalloc` on Void Linux is called `jemalloc-32bit`. So I went ahead and installed it via XBPS and copied `libjemalloc.so.2` to the Steam Flatpak root directory like so:
```
cp /usr/lib32/libjemalloc.so.2 ~/.var/app/com.valvesoftware.Steam/libjemalloc.so.2
```

Afterwards I used the `LD_PRELOAD` trick: Within the Steam window, right clicked on the game, clicked `Properties` and added the following to `Launch options`:
```
LD_PRELOAD=$LD_PRELOAD:/home/<username>/.var/app/com.valvesoftware.Steam/libjemalloc.so.2 %command%
```

This resulted in the same behavior: Steam didn't start the game and the logs complained about `libjemalloc.so.2` with this error: `TLS error: cannot allocate memory in static TLS block`

So I removed `jemalloc-32bit` from my system via XBPS and removed `~/.var/app/com.valvesoftware.Steam/libjemalloc.so.2` as well.

# The solution

I thought about it for a second and went googling for `source engine malloc bug linux`. These exact words spawned this first result: https://github.com/ValveSoftware/csgo-osx-linux/issues/2659

The first suggestion was to disable `Steam Input`, but for me it was already disabled. So I scrolled down and found this comment: https://github.com/ValveSoftware/csgo-osx-linux/issues/2659#issuecomment-1112233377 which referenced this comment from `lisa50469`: https://github.com/ValveSoftware/csgo-osx-linux/issues/2992#issuecomment-1108953999
> Running CSGO on Ubuntu 22.04 now. Had to do the following:
>
> cd ./.steam/debian-installation/steamapps/common/Counter-Strike\ Global\ Offensive/linux64/
> 
> mv libtcmalloc_minimal.so.0 libtcmalloc_minimal.so.0.orig
> 
> sudo apt install libtcmalloc-minimal4
> 
> cp /usr/lib/x86_64-linux-gnu/libtcmalloc_minimal.so.4.5.9 libtcmalloc_minimal.so.0

The command `sudo apt install libtcmalloc-minimal4` was what interested me. So I checked where to find the Void Linux equivalent of `libtcmalloc-minimal4`.

After some digging I found it within the Void Linux `shlibs`: https://github.com/void-linux/void-packages/blob/master/common/shlibs. Specifically this line: https://github.com/void-linux/void-packages/blob/master/common/shlibs#L1661
> `libtcmalloc_minimal.so.4 gperftools-2.1.90_1`

So I went ahead and installed `gperftools-32bit` via XBPS and copied `libtcmalloc_minimal.so.4.5.5` to the Steam Flatpak root directory like so:
```
cp /usr/lib32/libtcmalloc_minimal.so.4.5.5 ~/.var/app/com.valvesoftware.Steam/libtcmalloc_minimal.so.4.5.5
```

After changing the `Launch Options` of Counter-Strike Source to the following, it finally started to run as usual:
```
LD_PRELOAD=$LD_PRELOAD:/home/<username>/.var/app/com.valvesoftware.Steam/libtcmalloc_minimal.so.4.5.5 %command%
```

# What about native Steam installations?

Here, installing `gperftools-32bit` might fix the error without using the `LD_PRELOAD` trick. If not, try the following `Launch Options`:
```
LD_PRELOAD=$LD_PRELOAD:/usr/lib32/libtcmalloc_minimal.so.4.5.5 %command%
```

# What if libtcmalloc_minimal.so.4.5.5 doesn't exist on my system?

Depending on the installed version of `gperftools-32bit` and the corresponding version of `libtcmalloc_minimal`, the version string might be different for you, for example `4.5.6` instead of `4.5.5`.