[Ethereum] Link solc with geth problem

blockchaingo-ethereuminstallationsolcsolidity

After upgrading to geth 1.4.4 I am no longer able to from to reference the compiler from geth.

The solc compiler is installed in /usr/local/bin but this is what I get when I check for available compilers:

> eth.getCompilers();
I0520 10:22:45.501340 common/compiler/solidity.go:114] solc, the solidity compiler commandline interface
Version: 0.3.2-7a51852a/Release-Darwin/appleclang/JIT

path: /usr/local/bin/solc

[]

Then I try to set the compiler path again:

> admin.setSolc("/usr/local/bin/solc")
I0520 10:25:49.234999 common/compiler/solidity.go:114] solc, the solidity compiler commandline interface
Version: 0.3.2-7a51852a/Release-Darwin/appleclang/JIT

path: /usr/local/bin/solc
"solc, the solidity compiler commandline interface\nVersion: 0.3.2-7a51852a/Release-Darwin/appleclang/JIT\n\npath: /usr/local/bin/solc"

When I check the compilers again I still get:

> eth.getCompilers();
[]

I get the same using:

> web3.eth.getCompilers();
[]

I have reinstalled go-ethereum, npm.

Can anybody give me a hint of what to do or where to look to look.

I had no problems before upgrading to geth 1.4.4

Thanks in advance

Best Answer

Summary

Segmentation fault with solc version 0.3.2-7a51852a/Release-Darwin/appleclang/JIT ~~, fixed with later updated version~~.

UPDATE 26/06/2016

This is a bug in the Solidity compiler.

Here is a quick test:

user@Kumquat:~$ echo '' | solc
Unknown exception during compilation.

See eth.compile.solidity fails with solc version 0.3.5 #2703, which links to Exception on compilation from stdin #651.

And the issue Fix crash for input from stdin. #652 has been fixed, but will take an unknown (hopefully short) amount of time to make it into the repository packages.

This is the code change for the fix - Fix crash for input from stdin. #652 - Files changed.

You can try installing the previous version of solc.

Or one workaround offered in the first link above:

For anyone who wants a temporary workaround, you can clone this repo: https://github.com/mattdf/solidity-static and do a build in docker, then copy the solc file to your install. It makes a statically compiled build of solc so it should work on most distros.

Details

Check Solidity Compiler Within `geth`

I just checked by installation (Linux) and the output that you are getting is consistent with the output I get, but the compiler works correctly.

Run the test below to check if your compiler is configured correctly.

I'm using the following code:

contract Test { 
    function double(int a) constant returns(int) {
        return 2*a;
    } 
}

I've flattened the code above to:

> var testSource='contract Test {  function double(int a) constant returns(int) { return 2*a; } }'
undefined

I've tried compiling the code using the following statement:

> var testCompiled = web3.eth.compile.solidity(testSource);
undefined

And checked the results of the compilation:

> testCompiled
{
  Test: {
    code: "0x6060604052602a8060106000396000f3606060405260e060020a60003504636ffa1caa8114601a575b005b6002600435026060908152602090f3",
    info: {
      abiDefinition: [{...}],
      compilerOptions: "--bin --abi --userdoc --devdoc --add-std --optimize -o /tmp/solc935251869",
      compilerVersion: "0.3.2",
      developerDoc: {
        methods: {}
      },
      language: "Solidity",
      languageVersion: "0.3.2",
      source: "contract Test {  function double(int a) constant returns(int) { return 2*a; } }",
      userDoc: {
        methods: {}
      }
    }
  }
}

And if you want to check if the code runs correctly:

> var testContract = web3.eth.contract(testCompiled.Test.info.abiDefinition);
var test = testContract.new({
    from:web3.eth.accounts[0], 
    data: testCompiled.Test.code, gas: 2000000}, 
    function(e, contract) {
      if (!e) {
        if (!contract.address) {
          console.log("Contract transaction send: TransactionHash: " + contract.transactionHash + " waiting to be mined...");
        } else {
          console.log("Contract mined! Address: " + contract.address);
          console.log(contract);
        }
    }
})
...
Contract mined! Address: 0x5e3361efa79827d8a53a397b454770c6816585d7
> test.double(5)
10

Check Solidity Compiler

If you are still encountering problems, let's try compiling the source code outside geth.

Save the following code into Test.sol:

contract Test { 
    function double(int a) constant returns(int) {
        return 2*a;
    } 
}

From your terminal, you should be able to run the following commands if your solidity compiler is working correctly:

user@Kumquat:~$ solc --bin Test.sol

======= Test =======
Binary: 
606060405260728060106000396000f360606040526000357c0100000000000000000000000000000000000000000000000000000000900480636ffa1caa146037576035565b005b604b60048080359060200190919050506061565b6040518082815260200191505060405180910390f35b6000816002029050606d565b91905056

user@Kumquat:~$ solc --abi Test.sol

======= Test =======
Contract JSON ABI
[{"constant":true,"inputs":  [{"name":"a","type":"int256"}],"name":"double","outputs":[{"name":"","type":"int256"}],"type":"function"}]

If the commands above do not produce similar output, there is something not quite right with your solc binary.

Check `web3.js`

You have an error message that includes the text web3.js. The problem could be with this module. I'll update when I've researched it a bit more.

Related Solutions

[Ethereum] Can’t install solc on Mac OS X

I wasn't familiar with NPM, so had some similar issues. Simply running npm install solc will attempt to install locally, which can present some permission and linking issues- this is likely the cause of the problem.

Instead, install solC globally by using $ npm install -g solc (you may also want to try $ npm install solc --global as I'm not sure which of these two commands fixed my issue).

If this is installed, check where it's been installed by running $ which solcjs which should yield something like /usr/local/bin/solcjs

I found that I needed to also use Homebrew to install/build solC, following the installation instructions. Once Brew was done, I checked that solC was installed with $ which sol.

Copy this directory, then once you've launched geth console use it in the setSolc command, like > admin.setSolc("/usr/local/bin/solc")

With luck, you'll get a confirmation message, and the next time your run > eth.getCompilers() the result should be something like ["Solidity"]

Windows Solc Installation – How to Install Solc Compiler on Windows 8

One relatively easy solution is to install node.js and use the solc npm package. I used it myself when I initially started playing with ethereum contracts and it was a snap to set up.

Here are the steps -

install the latest version of node.js
create a folder for the project
add solc package to your package.json file, or use the following package file -

{ "name": "eth_compiler", "version": "0.0.1", "engines": { "node": ">=7.0.0", "npm": "^3.0.0" }, "dependencies": { "solc": "^0.4.7" } }
run npm install in the folder
add a small js script to the folder (compile.js) - it will receive the contract file name and output the abi/code files you need.

Here's a example -

var solc = require('solc');
var fs = require('fs');

var inputFilePath = process.argv[2];
var outputPath = process.argv[3];

// note - using the synchronous version of the file system functions for simplicity and because the async version isn't really needed in this case
var contractSolidity = fs.readFileSync(inputFilePath , 'utf-8');
if (!contractSolidity)
    return console.error('unable to read file: ' + inputFilePath );

var output = solc.compile(contractSolidity, 1);
for (var contractName in output.contracts) {
    var abi = output.contracts[contractName].interface;
    var code = output.contracts[contractName].bytecode;
    fs.writeFileSync(outputPath + '/' + contractName + '.abi', abi, 'utf-8');
    fs.writeFileSync(outputPath + '/' + contractName + '.code', code, 'utf-8');
}

once you have that file, you can simply execute the following command in the new folder - node compile [inputFilePath] [outputPath]

and it should generate the compiled files.

Note: I did test it locally and managed to compile a contract so I believe it should work but it's worth mentioning that I have both party & cpp-ethereum installed on my machine (parity wasn't running at the time of this script's execution).