Keywords: Python Virtual Environment | pyvenv Error | ensurepip Failure
Abstract: This article provides an in-depth analysis of the 'returned non-zero exit status 1' error encountered when creating Python 3.4 virtual environments using pyvenv-3.4 in Kubuntu 14.04. It systematically introduces two main solutions: fixing missing ensurepip module issues by installing python3.4-venv system packages, or using python-virtualenv tool to create compatible environments. Through comparative analysis of different approaches, complete operational procedures and troubleshooting guidelines are provided to help developers quickly resolve virtual environment configuration problems.
Problem Background and Error Analysis
When developers attempt to create Python 3.4 virtual environments using the pyvenv-3.4 venv command in Unix-based Kubuntu 14.04 systems, the system returns the error message: Error: Command '['/home/fmr/projects/ave/venv/bin/python3.4', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1. This error indicates that the ensurepip module execution failed during the virtual environment creation process.
Root Cause Analysis
The fundamental cause of this error lies in the Python 3.4 venv module's dependency on ensurepip to install the pip package manager, but the system lacks necessary venv support library files. When executing the pyvenv-3.4 command, the system attempts to invoke the ensurepip module in the newly created virtual environment, but due to missing or corrupted related files, the process exits with a non-zero status.
Solution One: Install System venv Support Packages
The most direct solution is to install complete Python 3.4 development environment support through the system package manager. Execute the following command:
sudo apt-get install python3.4-dev python3.4-venvAfter installation, create the virtual environment using the Python module approach:
python3.4 -m venv myVenvThis method ensures the system has complete venv functionality support and is the most stable and reliable solution.
Solution Two: Using virtualenv Tool
As an alternative approach, you can install and use the standalone virtualenv tool. First install the python-virtualenv package:
sudo apt-get install python-virtualenvThen create the virtual environment by specifying the Python 3.4 interpreter path:
virtualenv --python=/usr/bin/python3.4 venvThis method does not depend on the system venv module and offers better compatibility and stability.
Supplementary Solution Analysis
Referencing other solutions, you can also use the --without-pip parameter to create a virtual environment without pip, then manually install pip:
python3.4 -m venv --without-pip ./venv
source ./venv/bin/activate
curl https://bootstrap.pypa.io/get-pip.py | python
deactivate
source ./venv/bin/activateThis approach is suitable for situations with restricted network environments or unavailable system package management.
Best Practice Recommendations
Based on error analysis and solution comparison, it is recommended to prioritize Solution Two (using the virtualenv tool) because:
- The virtualenv tool is mature, stable, and offers better compatibility
- It does not depend on specific Python version venv module implementations
- It supports multiple Python versions and environment configurations
- It has extensive community support and well-documented resources
Extended Troubleshooting
If the above methods still cannot resolve the issue, check the integrity of the system Python installation to ensure all necessary dependency packages are correctly installed. In some cases, it may be necessary to manually download and place the wheel files required by ensurepip, as described in the reference article method.