Environment Triage
When uv sync or pip install behaves unexpectedly, check the actual interpreter.
Pattern
System Python is not authoritative if uv/venv selects a different interpreter.
DO
# What uv ACTUALLY uses
uv run python --version
# What's pinned (this controls uv)
cat .python-version
# Confirm package is installed
uv pip show <package>
# Confirm import works in uv context
uv run python -c "import <package>; print(<package>.__version__)"Common Fix
If optional deps require Python 3.12+ but .python-version is 3.11:
echo "3.13" > .python-version
rm -rf .venv && uv venv && uv sync --all-extrasDON'T
- Trust
python3 --versionwhen using uv - Assume install succeeded without verifying import
- Debug further before checking interpreter version
Source Sessions
- 2243c067: symbolica-agentica skipped due to
python_version >= 3.12marker, but uv was using 3.11 - 4784f390: agentica import failures traced to wrong interpreter