bug(`forge test`): `forge test` does not detect code changes

[thepluck]

Component

Forge

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

• Foundry
• Foundryup

What version of Foundry are you on?

forge Version: 1.3.1-v1.3.1 Commit SHA: 08d3a4a Build Timestamp: 2025-08-12T07:40:48.462796000Z (1754984448) Build Profile: maxperf

What version of Foundryup are you on?

foundryup: 1.3.0

What command(s) is the bug in?

forge test

Operating System

macOS (Apple Silicon)

Describe the bug

After changing the code, running forge test does not rebuild the changed files. It only rebuilds after running it again after several minutes or run forge clean.

[grandizzy]

@thepluck please provide more details (config you use like dynamic test linking?) and a way to repro this. I am not able to reproduce this with a simple Counter project. thank you

[thepluck]

# See more config options https://github.com/foundry-rs/foundry/blob/master/crates/config/README.md#all-options

## Profile configs
[profile.default]
src = 'contracts'
libs = ['node_modules', 'lib']
verbosity = 3
cache_path  = 'forge-cache'
fs_permissions = [{ access = 'read-write', path = './'}]
optimizer = true
optimizer_runs = 200
gas_reports = ['*']
ignored_error_codes = ['func-mutability', 'unused-var', 'unused-param']
evm_version = 'cancun'
ffi = true
no_match_path = "test/prod/*"
seed = 42
dynamic_test_linking = true

## Testing configs
[fuzz]
runs = 16
max_test_rejects = 100_000

[invariant]
depth = 16

## Format configs
[fmt]
line_length = 100
tab_width = 2
quote_style = 'single'
number_underscore = 'thousands'
sort_imports = true

Here is my foundry.toml. The repo is very large and private, so I could not share it with you. I will try to reproduce the behaviour with a stripped-down version.

[grandizzy]

thank you. I see you have dynamic_test_linking enabled, mind this won't rebuild tests when you change srcs, you can set it on false and retest your scenario

[zerosnacks]

After changing the code, running forge test does not rebuild the changed files. It only rebuilds after running it again after several minutes or run forge clean.

This sounds like the same issue @emo-eth described to me in person at Frontiers; a minimal reproduction would be greatly appreciated!

[grandizzy]

hey @thepluck any luck with providing a repro to debug? thank you

[thepluck]

Hi, I am currently busy with my work. I'll let you know if I find a way to reproduce the bug in the near future. Thanks.

[grandizzy]

ping @thepluck if you still experiencing the issue could you please update with a way to reproduce? This is quite important as we plan to turn feature on by default and use it in mutation testing as well. Thank you