Invalid arguments cause application crash (segfault) instead of raising an exception

[4dreadhead]

Invalid arguments cause application crash (segfault) instead of raising an exception

Description

When passing incompatible/invalid arguments to certain gem objects backed by the C++ OpenCV API, the entire Ruby process crashes with a segmentation fault instead of raising a proper Ruby exception (e.g. TypeError or ArgumentError).

This makes it impossible to rescue from such errors, and a single accidental misuse of the API brings down the whole application.

Steps to reproduce

require "opencv-ruby"

Cv::ThresholdTypes::THRESH_BINARY | 1  # crash
Cv::Scalar.new + 1                     # crash
Cv::Vec3b.new + 1                      # crash

Expected behavior

An appropriate Ruby exception should be raised (e.g. TypeError: no implicit conversion of Integer into ...), allowing the caller to rescue and handle the error gracefully.

Actual behavior

The Ruby process crashes with a segmentation fault. Segfault log attached.

Environment

• Gem: opencv-ruby
• Ruby: 4.0.1 (2026-01-13 revision e04267a14b) +PRISM
• OS: Ubuntu 23.04 (kernel 6.2.0-39-generic)

Notes

The operations themselves are logically invalid and are not expected to succeed - the issue is solely that the error surfaces as a native crash rather than a rescuable Ruby exception.

Fault info

fault.txt