/etc/upstream-release shipped as directory instead of file in Mint 22.3 (breaks gscan2pdf)

Description:
Linux Mint 22.3 appears to ship /etc/upstream-release as a directory instead of a file. This causes applications that read distro metadata (such as gscan2pdf) to fail when they attempt to open or close this path as a file.

Expected behavior -
/etc/upstream-release should be a regular file containing:
Code: DISTRIB_ID=Ubuntu

Actual behavior - Mint 22.3 installs:

Code
/etc/upstream-release/ ← directory
/etc/upstream-release/lsb-release
This structure is incorrect and causes tools to crash when they attempt to read /etc/upstream-release as a file.

Steps to reproduce:

Install Linux Mint 22.3 (Cinnamon in my case).
Inspect the path:
Code
ls -ld /etc/upstream-release
→ shows a directory
Launch gscan2pdf
→ application fails with an error related to closing /etc/upstream-release

Workaround:
Remove the incorrect directory and create the correct file:

Code
sudo rm -r /etc/upstream-release
echo "DISTRIB_ID=Ubuntu" | sudo tee /etc/upstream-release > /dev/null
After this correction, gscan2pdf and other tools work normally.

Notes:
This issue does not occur in Mint 21.x. Appears to be a regression introduced in the Mint 22.x series (Ubuntu 24.04 base). The incorrect directory likely originates from a packaging script or metadata generation step.

System: Linux Mint 22.3 (Cinnamon). Fully updated as of March 2026.

Start by reproducing the reported /etc/upstream-release layout on Linux Mint 22.3 and inspect the packaging or metadata-generation entry point that creates it. Done means the path is a regular file containing DISTRIB_ID=Ubuntu, and gscan2pdf no longer fails when reading or closing it.