"Not running with wine" error - Environment variables missing on launch (Arch Linux)

[Salvodif]

I am encountering an issue where wemod-launcher fails to start, displaying a popup error: "Error: Not running with wine."
The logs indicate that STEAM_COMPAT_DATA_PATH and WINEPREFIX environment variables are not set, causing the launcher to exit.

I followed the "Full Guide" installation method up to step 4. The issue occurs when the launcher attempts to run (it seems to be looping through virtual environment creation/checks).
To Reproduce

Install wemod-launcher via GitHub method on Arch Linux.
Follow the setup instructions (Full Guide).
Attempt to launch the application.

The error popup appears immediately (see screenshot).

System Information
OS: Arch Linux x86_64
Desktop Environment: GNOME (Wayland session)
Wemod-launcher Version: 1.535 (Git)
Proton Version: Proton 9.0-4
System Wine: 10.20 (Staging/Dev) [User Note: Please verify if this version number is correct, usually it is 9.x]

Logs
code
Text
148 │ The rerun nr 1 was started
149 │ The script wemod-launcher is running on version 1.535
150 │ No updates available
151 │ The STEAM_COMPAT_DATA_PATH and the WINEPREFIX / WINE_PREFIX_PATH environment variables were not set.
152 │ Most likely this is not running under wine. Exiting...
153 │
154 │
155 │
156 │ The script wemod-launcher is running on version 1.535
157 │ Package 'FreeSimpleGUI' is missing
158 │ Virtual environment is set in config, but was not passed, returning error to get the virtual environment next time
159 │ Virtual environment created successfully.
160 │ Pip finished successfully
161 │ No updates available
162 │ Re-running script within virtual environment;
163 │ or, to update or run outside the flatpak sandbox with the command:
164 │ ['/home/blackpraedicator/wemod-launcher/wemod_venv/bin/python', '/home/blackpraedicator/wemod-launcher/wemod', '--help']
165 │
166 │ The rerun nr 1 was started
167 │ The script wemod-launcher is running on version 1.535
168 │ No updates available
169 │ The STEAM_COMPAT_DATA_PATH and the WINEPREFIX / WINE_PREFIX_PATH environment variables were not set.
170 │ Most likely this is not running under wine. Exiting...

It seems the script is correctly setting up the Python virtual environment (wemod_venv), but when it re-runs itself inside the venv, it loses context of the Steam/Proton environment variables.

[shymega]

Closing in favour of #217.

[shymega]

Sorry, my bad, I trimmed too many characters off the issue ID.

@Salvodif See #217. Not #21.

But please, in future, search the bug tracker, and try and do some searching - a quick search of the bug tracker would show I moved your Q&A as a bug.