Truffle is currently using solc 0.7.0, but one or more of your contracts specify "pragma solidity ^0.6.0"

Support Contracts
1

I write pragma solidity ^0.7.0 and it give me mistake

Compiling your contracts...
===========================
> Compiling ./contracts/ICO.sol
> Compiling ./contracts/Migrations.sol
> Compiling ./contracts/Token.sol
> Compiling @openzeppelin/contracts/math/SafeMath.sol
> Compiling @openzeppelin/contracts/token/ERC20/ERC20.sol
> Compiling @openzeppelin/contracts/token/ERC20/IERC20.sol

CompileError: @openzeppelin/contracts/math/SafeMath.sol:3:1: ParserError: Source file requires different compiler version (current compiler is 0.7.0+commit.9e61f92b.Emscripten.clang) - note that nightly builds are considered to be strictly less than the released version
pragma solidity ^0.6.0;
^---------------------^
,@openzeppelin/contracts/token/ERC20/ERC20.sol:3:1: ParserError: Source file requires different compiler version (current compiler is 0.7.0+commit.9e61f92b.Emscripten.clang) - note that nightly builds are considered to be strictly less than the released version
pragma solidity ^0.6.0;
^---------------------^
,@openzeppelin/contracts/token/ERC20/IERC20.sol:3:1: ParserError: Source file requires different compiler version (current compiler is 0.7.0+commit.9e61f92b.Emscripten.clang) - note that nightly builds are considered to be strictly less than the released version
pragma solidity ^0.6.0;
^---------------------^

Error: Truffle is currently using solc 0.7.0, but one or more of your contracts specify "pragma solidity ^0.6.0".
Please update your truffle config or pragma statement(s).
(See https://trufflesuite.com/docs/truffle/reference/configuration#compiler-configuration for information on
configuring Truffle to use a specific solc compiler version.)

Compilation failed. See above.
    at run (/home/asven/.nvm/versions/node/v14.15.0/lib/node_modules/truffle/build/webpack:/packages/compile-solidity/run.js:51:1)
    at Object.sourcesWithDependencies (/home/asven/.nvm/versions/node/v14.15.0/lib/node_modules/truffle/build/webpack:/packages/compile-solidity/index.js:107:49)
    at necessary (/home/asven/.nvm/versions/node/v14.15.0/lib/node_modules/truffle/build/webpack:/packages/compile-solidity/index.js:69:1)
    at /home/asven/.nvm/versions/node/v14.15.0/lib/node_modules/truffle/build/webpack:/packages/workflow-compile/index.js:38:1
    at async Promise.all (index 0)
    at compile (/home/asven/.nvm/versions/node/v14.15.0/lib/node_modules/truffle/build/webpack:/packages/workflow-compile/index.js:28:1)
    at Object.compile (/home/asven/.nvm/versions/node/v14.15.0/lib/node_modules/truffle/build/webpack:/packages/workflow-compile/index.js:67:38)
Truffle v5.1.54 (core: 5.1.54)
Node v14.15.0
in truffle-confige.js  solc ^0.7.0
1 Like
2

Hi @asven-2020,

The details of your post were hidden in comments, I have edited your post.

If you want to use OpenZeppelin Contracts 3.x with Solidity 0.7 you can install the Solidity 0.7 variant:

npm install @openzeppelin/contracts@solc-0.7

See: OpenZeppelin Contracts 3.2

3

Hallo abcoathup,

Problem that 3.x havent crouwdsale, all it in openzeppelin-solidity 2.x cant find better version in this case i must do token in solc 0.5.6
or may be you can recommend better

1 Like
4

Hi @asven-2020,

If you want to use OpenZeppelin Contracts 2.x then you can install with:

npm install @openzeppelin/contracts@2.5.1

OpenZeppelin Contracts 2.x uses Solidity 0.5.

For crowdsale documentation: https://docs.openzeppelin.com/contracts/2.x/crowdsales

You could have one project for your token and one project for your crowdsale, but it may be simpler to just use OpenZeppelin Contracts 2.x for both.

5

ok thank you

but if i also take this token to another place I havent problem in version

1 Like