Cannot install Python dependencies in 'pip install -r requirements.txt' due to send2trash parsing error

hong_yoonki · November 10, 2025, 1:29pm

I followed the official setup guide

doc/basic-pipelines.md

main

# Hailo RPi5 Basic Pipelines
This repository contains examples of basic pipelines using Hailo's H8 and H8L accelerators. The examples demonstrate object detection, human pose estimation, and instance segmentation, providing a solid foundation for your own projects.
This repo is using our [Hailo Apps Infra](https://github.com/hailo-ai/hailo-apps-infra) repo as a dependency.
See our Development Guide for more information on how to use the pipelines to create your own custom pipelines.

## Installation
See the [Installation Guide](../README.md#installation) in the main README for detailed instructions on setting up your environment.

# Overview

This guide provides an overview of how to develop custom applications using the basic pipelines provided in this repository. The examples demonstrate object detection, human pose estimation, and instance segmentation using Hailo's H8 and H8L accelerators.

## Understanding the Callback Method

Each example in this repository uses a callback method to process the data from the GStreamer pipeline. The callback method is defined as a function that is called whenever data is available from the pipeline. This function processes the data, extracts relevant information, and performs any necessary actions, such as drawing on a frame or printing information to the terminal.

### User App Callback Class

The `user_app_callback_class` is a custom class that inherits from the `app_callback_class` provided by the `hailo_apps_infra` package. This class is used to manage user-specific data and state across multiple frames. It typically includes methods to increment frame counts, manage frame data, and handle any additional user-specific logic.

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./install.sh completes, but step

pip install -r requirements.txt

fails. I’m getting repeated warnings like:

Requirement already satisfied: wheel in ./venv_hailo_rpi_examples/lib/python3.11/site-packages (0.45.1)
warning: error parsing dependencies of send2trash: expected matching RIGHT_PARENTHESIS for LEFT_PARENTHESIS, after version specifier
sys-platform (=="darwin") ; extra == 'objc'

And during the ./install.sh step I also saw the same errors many times, although the installation did complete.

omria · November 10, 2025, 2:02pm

Hey @hong_yoonki,

Welcome to the Hailo Community!

Just a heads up - you don’t need to run the requirements.txt install separately since install.sh already handles that for you. As for the error you’re seeing in install.sh, that’s strange and shouldn’t be happening.

If install.sh finished successfully, the app should be working fine. Could you do me a favor and run pip list | grep hailo both inside and outside the virtual environment? That’ll help us figure out what’s going on.

hong_yoonki · November 11, 2025, 4:46am

his error message appears many times during ./install.sh, but the installation still completes successfully. More importantly, both the detection examples and the camera examples run correctly. It seems like this is a harmless warning that can be ignored.
Thanks for your reply.