Limitations around non-isolated builds - Lix Reference Manual

# Limitations of non-isolated builds

## What are non-isolated builds?

In Lix, only builds done on Linux with `sandbox = true` and a functioning `pasta-path` are isolated from the rest of the system, all other builds are considered non-isolated to some degree.

For example, running Lix with Pasta disabled makes the host network visible to fixed-output derivations, reducing isolation somewhat.

## Clean termination of non-isolated builds

Non-isolated builds may not terminate cleanly in all cases due to limitations in Lix's process management.

This occurs when a build keeps the build log file descriptor open past the end of the actual build. A common cause of this are background tasks that aren't properly terminated before the main build process exits, for example: HTTP servers run as part of a test suite.

See issue #1018 for an example.

The only solution is to manually terminate leftover processes in your derivation, including during failure scenarios.