solc. finished with non-zero exit value 1

[ivica7]

I am using this sample app to experiment with my own contracts. My own contracts require solidity compiler 0.5.0+, so I've changed the gradle file to set the solidty version correspondingly.

pragma solidity ^0.5.0;
contract XXX {...}

web3j {
    ...
    solidity {
        version = '0.5.0'
    }
}

When I start the gradle build I always get the following error:
Execution failed for task ':compileSolidity'.

Process 'command '/var/folders/4d/rwvvzqh10nx5x9qg3yw8jsz00000gn/T/solc/solc'' finished with non-zero exit value 1

If I set pragma to
pragma solidity ^0.4.0;

it works. It seems to me the build process is not respecting the solidity version set.