hermes - 💡(How to fix) Fix Bug: uv venv venv --python 3.11 causes severe memory spike during installation [1 comments, 1 participants]

Bug: uv venv venv --python 3.11 causes severe memory spike during installation

Summary

During the installation of hermes-agent, the system runs out of memory when creating the Python virtual environment with uv.

The problematic command is:

cd /opt/hermes-agent && uv venv venv --python 3.11 2>&1

This step rapidly consumes available RAM until the Linux OOM killer starts terminating processes.

Observed behavior

When the command above is executed, memory usage increases very quickly. The system eventually enters an OOM condition and starts killing unrelated processes.

Example OOM output:

Out of memory: Killed process ... (systemd)
Out of memory: Killed process ... ((sd-pam))
Out of memory: Killed process ... (.opencode) total-vm:74764388kB
Out of memory: Killed process ... (unattended-upgr)
Out of memory: Killed process ... (uv)
Out of memory: Killed process ... (rsyslogd)

The most notable part is that .opencode shows extremely high virtual memory usage:

(.opencode) total-vm:74764388kB

This suggests that uv may not be the only process involved, or that another process is triggered or active during this installation step.

Expected behavior

Creating the virtual environment should complete without exhausting system memory:

uv venv venv --python 3.11

Expected result:

• virtual environment created successfully
• no OOM condition
• no unrelated processes killed

Actual behavior

The system rapidly consumes available RAM during the uv venv step and then becomes unstable due to OOM killer activity.

Reproduction step

Run the following during installation:

cd /opt/hermes-agent && uv venv venv --python 3.11 2>&1

Why this looks suspicious

Creating a Python virtual environment should normally be a lightweight operation. It should not consume massive amounts of memory or cause the OOM killer to terminate unrelated system services.

The issue may be related to one of the following:

• uv resolving or downloading Python 3.11 unexpectedly
• a parallel or background process being triggered during this step
• .opencode interacting with the installation process
• recursive or uncontrolled process spawning
• an installation script starting additional processes while the venv is being created

Suggested investigation

Please check whether the installation flow can accidentally trigger or interact with other processes while this command is running:

uv venv venv --python 3.11

It may also be worth documenting or recommending the explicit Python path variant:

uv venv venv --python /usr/bin/python3.11

to avoid unexpected Python resolution behavior.

Impact

The installation cannot reliably proceed because this step can consume all available RAM and trigger the OOM killer.