Developers' Guide

Build and test

Go environment

We assuming that you have go installed, GOPATH is set.

Note:You must have your working copy under $GOPATH/src/github.com/ethereum/go-ethereum.

Since go does not use relative path for import, in working in any other directory will have no effect, since the import paths will be appended to $GOPATH/src, and if the lib does not exist, the version at master HEAD will be downloaded.

Most likely you will be working from your fork of go-ethereum, let's say from github.com/nirname/go-ethereum. Clone or move your fork into the right place:

git clone [email protected]:nirname/go-ethereum.git $GOPATH/src/github.com/ethereum/go-ethereum

Godep for dependency management

As of POC-8, go-ethereum uses Godep to manage dependencies.

Istall godep:

go get github.com/tools/godep

Make sure that go binaries are on your executable path:

PATH=$GOPATH/bin:$PATH

godep should be prepended to all go calls build, install and test.

Alternatively, you can prepend the go-ethereum Godeps directory to your current GOPATH:

GOPATH=`godep path`:$GOPATH

Building executables

Switch to the go-ethereum repository root directory (Godep expects a local Godeps folder ).

Each wrapper/executable found in the cmd directory can be built individually.

To build the CLI:

godep go build -v ./cmd/ethereum

Building Mist (GUI)

For the GUI, you need to install QT5 and set variables.

On OSX with a brew install of qt5:

export PKG_CONFIG_PATH=/usr/local/Cellar/qt5/5.4.0/lib/pkgconfig
export CGO_CPPFLAGS=-I/usr/local/Cellar/qt5/5.4.0/include/QtCore/5.4.0/QtCore
export LD_LIBRARY_PATH=/usr/local/Cellar/qt5/5.4.0/lib

See the instructions on the wiki

With these prerequisites in place, compile mist with:

godep go build -v ./cmd/mist

Mist does not automatically look in the right location for its GUI assets. For this reason you need to launch it from its build directory

cd $GOPATH/src/github.com/ethereum/go-ethereum/cmd/mist && mist

or supply an absolute -asset_path option:

mist -asset_path $GOPATH/src/github.com/ethereum/go-ethereum/cmd/mist/assets

Testing

Testing one library:

godep go -v -cpu 4 test ./eth  

Using options -cpu (number of cores allowed) and -v (logging even if no error) is recommended.

Testing only some methods:

godep go -v -cpu 4 test ./eth -run TestMethod

Note: here all tests with prefix TestMethod will be run, so if you got TestMethod, TestMethod1, then both!

Running benchmarks, eg.:

cd bzz
godep go test -v -cpu 4 -bench . -run BenchmarkJoin

for more see go test flags

Add and update dependencies

To update a dependency version (for example, to include a new upstream fix), run

go get -u <foo/bar>
godep update <foo/...>

To track a new dependency, add it to the project as normal than run

godep save ./...

Changes to the Godeps folder should be manually verified then commited.

To make life easier try git flow it sets this all up and streamlines your work flow.