Problem with imports

[aathan]

$ forge --version
forge 0.2.0 (06f7c9c 2023-03-18T00:08:48.50351195Z)

I'm assuming the canonical way to import .sol files from the instant project is by specifying either no relative import directory or by specifying "./", correct?

Well, it seems that if foundry.toml includes 'lib' in its libs = [...,'lib'] definition, then import resolution fails. I'm suspecting some kind of problem in the import resolution module that foundry may be providing to solc? Or some kind of remapping issue? Or a collision with the directory structure of some of the projects in lib/ ???

Basically, with lib defined in this toml:

[profile.default]
src = 'src'
out = 'out'
libs = ['node_modules','lib']
remappings = [
    '@ensdomains/=node_modules/@ensdomains/',
    '@ethereum-waffle/=node_modules/@ethereum-waffle/',
    'hardhat/=node_modules/hardhat/',
]

... something weird is happening where the import "./ImportedFile.sol"; fails as follows:

$ forge build --force
[⠊] Compiling...
[⠒] Compiling 51 files with 0.8.19
[⠆] Solc 0.8.19 finished in 28.34ms
Error: 
Compiler run failed
error[6275]: ParserError: Source "lib/prb-contracts/src/ImportedFile.sol" not found: File not found. Searched the following locations: "/home/user/src/project/backend/contracts".
  --> src/ContactDoingTheImport.sol:32:1:
   |
32 | import "./ImportedFile.sol";
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

... and after some spelunking, it appears that the issue is that prb-contracts contains a remappings.txt that defines:

src/=src/

So what I think is happening is that ./ImportedFile.sol is resolving to src/ImportedFile.sol relative to the project root, but then whatever foundry is doing with remapping.txt files is causing that to resolve to the prb-contracts content.

Should foundry be using remappings.txt from lib projects? Shouldn't those remappings be translated to be relative to lib/... if so?

Removing the src/=src/ from lib/prb-contacts/remappings.txt fixes the problem.

Also, I'm having trouble finding wherever it is that clarifies how the .toml remappings entry relates to remappings.txt, and how those may or may not be merged, which takes precedence etc. I might suggest that foundry generate a comment in the .toml about that, and/or support comments in remappings.txt and insert a similar comment there, so that noobs don't have to go searching for this information.

Filed as #4597