Can't import openzeppelin node_modules: File import callback not supported

Question

Whenever I try to compile my solidity contract, the error ParserError: Source \"@OpenZeppelin/contracts/math/SafeMath.sol\" not found: File import callback not supported gets thrown.

pragma solidity ^0.7.0;

import "@OpenZeppelin/contracts/token/ERC20/ERC20.sol";
import "@OpenZeppelin/contracts/math/SafeMath.sol";

Any ideas what could be causing this?

Palomino

are you using VSCode plugin to compile it? – Mortal

See my solidity node_module referencing here https://mcmap.net/q/418238/-file-import-callback-not-supported – Magazine

Does this answer your question? File import callback not supported? – Industrial

If you read the VS Code extension docs (I am using the extension by Juan Blanco), it has a section about openzepplin. You need to edit your settings and add the following (assuming node_modules is in the root dir of your ptoject) : "solidity.packageDefaultDependenciesContractsDirectory": "", "solidity.packageDefaultDependenciesDirectory": "node_modules" – Savick

Answer 1

Make sure you opened VS Code in the root directory of the project.

In my case, this is how my VS Code directory looked like when I get that same error.

projects
 |___MyContract
   |__contracts
     |__Contract.sol

Reopening VS Code in the MyContract directory fixes it.

MyContract
 |__contracts
   |__Contract.sol

Lucinalucinda

This fixed it for me, was using a project cloned from github. – Melanoid

Answer 2

I have the same problem right now. I'm using truffle+node and I fixed it modifying the import path to a relative path, for example,

pragma solidity ^0.7.0;

import "../node_modules/OpenZeppelin/contracts/token/ERC20/ERC20.sol";
import "../node_modules/OpenZeppelin/contracts/math/SafeMath.sol";

I'm not 100% sure why this happen but I hope I helped you.

Rivet

Answer 3

After installing OpenZeppelin close your IDE and re-open it.

Bruges

You're right, hahaha. The Solidity plugin for VSCode is to blame, I suppose. I edit: the annoying error didn't go away. – Bobbyebobbysocks

@Bobbyebobbysocks make sure the import path is correct – Bruges

Answer 4

For some environments, SafeMath has a different path

import "@openzeppelin/contracts/utils/math/SafeMath.sol";

Othello

This was the solution for me. – Aguste

Answer 5

what worked for me; (I am using Windows10 and visual studio code) -click on the extensions icon -search for the solidity extension -select the uninstall button and click on the drop down arrow -select install another version -select version 0.0.135 -After the installation, click on "Reload required"

Polygon

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center. – Whoremaster

I had a similar bug with version 0.0.163 installed and switching to a previous version fixed the issue(I switched to v0.0.153). – Autophyte

Answer 6

Make sure you installed openzeppelin

npm install --save @openzeppelin/[email protected]

Japeth

Answer 7

actualy the problem is solidity compiler is stupid and doesn't automatically follow path, you have to specify all allowed path manually (https://docs.soliditylang.org/en/latest/using-the-compiler.html), every each one of them and completely to the file(cannot give juste the higher level folder) use npx hardat compile if you can it's better

Cedar

Answer 8

This worked for me -

Change the settings in Solidity extension in VSCode.

The default settings include: "solidity.packageDefaultDependenciesContractsDirectory": "contracts" Users need to change the setting from contracts to an empty string. "solidity.packageDefaultDependenciesContractsDirectory": ""

Source - https://github.com/juanfranblanco/vscode-solidity/issues/178

Krusche

Answer 9

Try this:

import "{Project Name}/node_modules/@openzeppelin/contracts/token/ERC20/ERC20.sol";

Brentonbrentt