bug(invariant): unbounded memory usage in long invariant testing runs

[rappie]

Component

Forge

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge Version: 1.4.4-nightly Commit SHA: 65f96cf Build Timestamp: 2025-10-31T06:02:26.081956256Z (1761890546) Build Profile: maxperf

What version of Foundryup are you on?

foundryup: 1.0.0

What command(s) is the bug in?

forge test -vv --show-progress --match-test invariant

Operating System

Linux

Describe the bug

When running invariant testing overnight I noticed it was using more than 100GB of memory.

You can reproduce it using the command listed above on the following repo (use this commit hash):
perimetersec/origin-woeth-fuzz@be6e4df

[0xalpharush]

Can you share some additional info like how many threads and the progress/log output (use show_progress or https://getfoundry.sh/config/reference/testing#show_edge_coverage)?

test/forge/invariant/StaticInvariantTest.sol:StaticInvariantTest
 → invariantHealthy: [60/2000] Runs
  - cumulative edges seen: 41
  - cumulative features seen: 6
  - corpus count: 15
  - favored items: 14

I was going to suggest lowering corpus_min_size, but it looks like the default is 0 and you don't have it configured...

Would you see if lowering corpus_min_mutations has impact on the memory usage? If it's not the corpus/coverage map that's using the memory, it could be include_storage or some other feature that collects values from observing the campagin.

[rappie]

It takes a long time to reproduce this. I'm currently in the middle of an engagement and I don't have the bandwidth to do this.

I'm happy to revisit this in about one month. However, you should be able to reproduce this yourself quite easily by using my repo.

To answer your first question: I'm using 12 threads. You can see this here as well.