Allow specifying guest trace level for different modules

We currently have a single trace level for everything inside the guest (all the modules).
We currently have no way to specify a trace level for the guest but a different one for the host (for the same module).
I'll make a separate issue to tackle this.

This is possible to imply a change of API for the entrypoint.

Moreover, we should think of a way to do this per guest call, because going forward, taking a snapshot after creation means the trace level cannot be changed afterwards.

Linked to #1268

#1833 covers most of this:

The guest level is set separately from the host with SandboxBuilder::guest_log_level and Sandbox::log_level. It no longer depends on RUST_LOG.
The level can change after a snapshot. Sandbox::log_level applies to future guest calls, and restore() reapplies it. Calling it before a call gives per-call control. The entrypoint API did not change.

Not covered: per-module guest levels. The guest gets one level for all modules. Supporting directives like my_guest::net=trace,warn means sending a variable-length filter to the guest, which today receives a single u64 in scratch memory

Navigation Menu

Repository navigation

Allow specifying guest trace level for different modules #1269

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Allow specifying guest trace level for different modules #1269

Description

Activity

simongdavies commented on Mar 11, 2026

ludfjig commented on Oct 22, 2026

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions