ggml-org/llama.cpp

Eval bug: Model loading fails on Windows when path contains non-ASCII (Cyrillic) characters

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#18571 opened on Jan 3, 2026

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bughelp wanted

Description

Name and Version

b7539 On Windows: Currently, llama.cpp attempts to open GGUF files using fopen, which fails when the path contains Cyrillic characters. gguf_init_from_file: failed to open GGUF file 'D:\Загрузки\models\llm\olmOCR-2-7B-1025-Q4_K_M.gguf'. For example, any ASCII characters are not supported, and the app throws an error. This means that any "Russian," "Chinese," "Korean," or any other characters in the path faild to load model.

Operating systems

Windows

GGML backends

Vulkan

Hardware

Ryzen 9 5900x + RTX 4090

Models

olmOCR-2-7B-1025-Q4_K_M Qwen2.5-VL-7B-Instruct-Q4_K_M

Problem description & steps to reproduce

On Windows, create a directory with Cyrillic characters, e.g.:

  1. for exempel D:\Загрузки\models\
  2. Place a .gguf model file inside.
  3. Load the model using llama.cpp
  4. Model loading fails with failed to open GGUF file.

First Bad Commit

No response

Relevant log output

Contributor guide

Tech stack
cpp
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
basic C++Windows file I/OUnicode handling
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Investigate the file loading functions in llama.cpp, particularly where `fopen` is used to open GGUF files. On Windows, `fopen` does not support UTF 8 paths in all locales. The fix likely involves switching to ` wfopen` or using `CreateFileW` with wide character strings. Review existing code in `gguf.cpp` or similar files that handle file opening. Check if there are any existing platform specific macros or if the codebase uses `std::ifstream` which might handle it differently. The issue comments may provide additional context or suggested approaches.