Install (and download) missing dependencies automatically

[shekhirin]

Component

Forge

Describe the feature you would like

I tried to run tests for the repo I've just cloned and it failed due to missing dependencies:

➜  mev-example git:(curve20220521) ✗ forge test --fork-url $ETH_RPC_URL --fork-block-number 14811888 -vvv
[⠊] Compiling...
Error:
Failed to resolve file: "/Users/shekhirin/Projects/mev-example/lib/forge-std/src/Test.sol": No such file or directory (os error 2).
 Check configured remappings.

After installing them, all worked as expected:

➜  mev-example git:(curve20220521) ✗ forge install
➜  mev-example git:(curve20220521) forge test --fork-url $ETH_RPC_URL --fork-block-number 14811888 -vvv
[⠒] Compiling...
[⠔] Compiling 16 files with 0.8.14
[⠒] Solc 0.8.14 finished in 1.35s
Compiler run successful

Running 1 test for test/MEV.t.sol:MEVSimulation
[PASS] testMEV() (gas: 2043432)
Test result: ok. 1 passed; 0 failed; finished in 476.13ms

---

I think there's two ways we can improve it:

1. Improve error message because current tells us only about remappings check.
2. Install and download missing dependencies behind the scenes like cargo does it:
   

Additional context

No response

[mattsse]

Improve error message because current tells us only about remappings check.

definitely

Install and download missing dependencies behind the scenes like cargo does it:

this will require a bit of work, basically managing a registry, but would be huge, getting rid of git submodules entirely would be amazing.

this would require

• dependency section in foundry.toml
• registry model for ~/.foundry/registry/...
• some libgit2 utils to create checkouts, used some of cargo's code for that in the binder create already
• ...

[shekhirin]

this will require a bit of work, basically managing a registry

i think forge install invocation before every command that may require deps would work as an MVP? if it doesn't take too much time of course

[onbjerg]

If we end up doing a dependency section in foundry.toml I'd ask if we could design it in a way where git is one way to install (the only supported way currently) so we can expand it later if needed. There's been quite a few issues/discussions about doing an alternative to Git submodules, so allowing for that in a dependencies section would future proof us a bit

[onbjerg]

@shekhirin Opened a PR for the quickfix in #2617, moved the discussion around better package management into #2618