Error: Couldn't find ethers-v5 (yarn workspaces)

[smartcontracts]

I'm getting the following error on the latest version of typechain:

Error: Couldn't find ethers-v5. Tried loading: @typechain/ethers-v5, typechain-target-ethers-v5, /home/k/Projects/work/optimism/packages/contracts/ethers-v5.
Perhaps you forgot to install @typechain/ethers-v5?

This is happening within a yarn/lerna monorepo. It appears this is happening because the typechain package is being hoisted to the root level, but the @typechain/ethers-v5 package is not.

[aspiers]

I had this too. It went away when I bumped typechain from 5.2.0 to 7.0.0 but that was probably just luck.

[aspiers]

Turns out it was just luck indeed. The issue randomly reappeared later even after upgrading to 7.0.0. After much trial and error, the only thing which fixed it for me was:

"nohoist": [
  "**/typechain",
  "**/@typechain/*"
]

[krzkaczor]

@smartcontracts does @aspiers fix work for you? yarn monorepos can be a mess...

[smartcontracts]

I'll give this fix a shot tomorrow and report back to you!

[krzkaczor]

@smartcontracts let me know. Also if you have a PR that I can look at that it could make debugging easier.

My bet would be that yarn decided to spread dependencies into a different tree after the upgrade and that's why it doesn't work now (note that waffle has a dependency on the old typechain version which make also affect your case).

[hasparus]

Just FYI, I've made target resolution more robust in the new version, so this should (no guarantees) be solved after the release.