How to upgrade solidity compiler in truffle

Question

I couldn't find a way to upgrade a version of truffle solidity compiler. Also curious how to see that information for deployed contracts in truffle console

Answer 1

You can force truffle to use a specific solc version by installing that version directly in the truffle directory.

For example on Ubuntu the following with force truffle to use 0.4.15

$ cd /usr/local/lib/node_modules/truffle
$ npm install [email protected]

truffle version will still show the default version but it will in fact utilize the updated version.

You can verify inside: /usr/local/lib/node_modules/truffle/package.json

...
"bundleDependencies": false,
  "dependencies": {
    ...
    "solc": "^0.4.15"
  },

Locations on Windows

%AppData%\npm\node_modules\truffle
%AppData%\npm\node_modules\truffle\package.json

Answer 2

If you're using ^v5.0.0 (including beta releases), you can bring your own compiler by adding this in your truffle config file (in this example it's set to 0.4.25):

module.exports = {
  ...
  compilers: {
    solc: {
      version: "0.4.25",
    },
  },
  ...
};

You can query the list of available compiler versions by running this:

truffle compile --list

Answer 3

After a couple of attempts, I've made it by uninstalling and installing truffle, exactly as described in here:

npm uninstall -g truffle
npm install -g truffle

That updated Truffle itself though, along with the compiler.

Answer 4

You need to upgrade your truffle to do that.

npm install -g truffle@X

For example, to get solc 0.4.11 support, install truffle 3.2.2 or above.

npm install -g [email protected] 

or

npm update -g [email protected]

Answer 5

Check your solc compiler version using the following command -

solc --version

Then you can use following commands to uninstall solc(solidity) compiler and install it again. It shall give you latest version(0.4.11) -

npm uninstall solc -g
npm install [email protected]

Check the solc version after installing it again.

In order to see the information of contracts, once you login to truffle console and run "compile" and "migrate" one by one. After that, You just need to type your ContractName or ContractName.abi to get the contract information.

Answer 6

On your project root directory, there's a file named "truffle-config.js"

Inside this file, you can find a solc config, and uncomment version line, and then put your prefer version. (ex: 0.5.7)

compilers: {
    solc: {
       version: "0.5.7",    // Fetch exact version from solc-bin (default: truffle's version)
      // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
      // settings: {          // See the solidity docs for advice about optimization and evmVersion
      //  optimizer: {
      //    enabled: false,
      //    runs: 200
      //  },
      //  evmVersion: "byzantium"
      // }
    }
  }

After this, just compile and truffle will download that version of solc automatically!

$ truffle compile 

Answer 7

Run uninstall and then install commands to get your Truffle and solc compiler upgraded to the latest version:

npm uninstall -g truffle
npm install -g truffle

Important: you may need to close the terminal and open it again to use the latest version.

Note: to check your current version execute:

truffle version

Answer 8

In the latest truffle after 5.x.x, it is possible to specify compiler version in truffle-config.js:

module.exports = {
  networks: {
    ... etc ...
  },
  compilers: {
     solc: {
       version: <string>  // ex:  "0.4.20". (Default: Truffle's installed solc)
     }
  }
};

Reference: https://github.com/trufflesuite/truffle/releases/tag/v5.0.0-beta.0#specify-a-solcjs-version

Answer 9

just responding as faced this issue in July 2020 and it took me quite a while to fix it as there aren't many resources for Solidity v0.6

So, here are things that I did to get my code compiled successfully.

1. Update Truffle, if you installed truffle before a significant amount of time to your development(I used it for a gig 6 months after I installed it as I was just playing around at the time and didn't started learning "actively" until recently).

2. Set compiler version for in "truffle-config.js" (make sure to use the current version as if you are using a library like OpenZeppelin-Contracts as there might be contracts in there using a different version of solidity than yours.

3. Usually, the second solution should be enough for you to get up and running. But In my case, I had to manually install "Solc" with "npm install solc" (inside your project directory). This installed solidity compiler 0.6.10 for me.

Yes, it required me to do all three steps to get my code to compile successfully. I hope this helps someone

Answer 10

You need not to uninstall truffle just install your required version by these commands. For Ubuntu 16.04(suppose I want truffle v4.1.7):

sudo npm install -g [email protected]

Check truffle version:

truffle version

For any help with truffle commands:

truffle --help

Answer 11

If you just installed Truffle and want to use older version of Solidity, you can simply specifying the compiler version in the truffle-config.js file:

  ...
  // Configure your compilers
  compilers: {
    solc: {
      version: "0.5.11", // Fetch exact version from solc-bin (default: truffle's version) 
      ...
    }
  }
  ...

If this doesn't work for you and you are compiling your contracts using VS Code extension, most likely you will have to change the compiler version of the extension. Check this answer to find out more.

If you want to use newer version, you will have to upgrade or re-install Truffle itself. To check the latest version of the compiler, type truffle compile --list

Answer 12

As @Adam Lemmon suggested, you can hardcode the version that the global truffle installation is using, or you can just update the version in the pragma solidity ^0.4.15; statement of your contract.

Note: This will only work if you are not inheriting from any other contracts. If the parent contracts use a higher solidity version, you'll get the compilation errors.

Answer 13

You can't specify version, but we can specify some params as well: http://truffleframework.com/docs/advanced/configuration#solidity-compiler-configuration

solc: {
  optimizer: {
    enabled: true,
    runs: 200
  }
}

https://github.com/poanetwork/poa-bridge-contracts/blob/master/truffle.js#L49

Answer 14

I used next commands upgrade truffle when I want to compile solidity version: pragma solidity ^0.4.25;

npm uninstall -g truffle
npm install -g truffle@beta

Answer 15

I messed around with manually changing the installed truffle package's solc dependency, however the versions weren't compatible, it wouldn't run my tests properly and it felt very hacky.

Instead I just installed the truffle package that naturally had a dependency on the solc version I wanted. In my case I wanted solc": "0.4.24" so I installed "truffle": "4.1.14".