anchor.diff:  # build the image:
   #   docker build -t restic/test .
   #
  -# run tests:
  -#   docker run --rm -v $PWD:/home/travis/gopath/src/github.com/restic/restic restic/test go run run_integration_tests.go
  +# run all tests and cross-compile restic:
  +#   docker run --rm -v $PWD:/home/travis/restic restic/test go run run_integration_tests.go -minio minio
   #
  -# run interactively with:
  -#   docker run --interactive --tty --rm -v $PWD:/home/travis/gopath/src/github.com/restic/restic restic/test /bin/bash
  +# run interactively:
  +#   docker run --interactive --tty --rm -v $PWD:/home/travis/restic restic/test /bin/bash
   #
  -# run a tests:
  -#   docker run --rm -v $PWD:/home/travis/gopath/src/github.com/restic/restic restic/test go test -v ./backend
  +# run a subset of tests:
  +#   docker run --rm -v $PWD:/home/travis/restic restic/test gb test -v ./backend
  +#
  +# build the image for an older version of Go:
  +#   docker build --build-arg GOVERSION=1.3.3 -t restic/test:go1.3.3 .
   
   FROM ubuntu:14.04
   
  -ARG GOVERSION=1.5.3
  +ARG GOVERSION=1.6
   ARG GOARCH=amd64
   
   # install dependencies
  
positive.code:     && chmod +x $HOME/bin/minio
  
  # set TRAVIS_BUILD_DIR for integration script
  ENV TRAVIS_BUILD_DIR $GOPATH/src/github.com/restic/restic
  ENV GOPATH $GOPATH:${TRAVIS_BUILD_DIR}/Godeps/_workspace
  
  WORKDIR $TRAVIS_BUILD_DIR
  
negative.code: RUN wget -q -O /tmp/go.tar.gz https://storage.googleapis.com/golang/go${GOVERSION}.linux-${GOARCH}.tar.gz
  RUN tar xf /tmp/go.tar.gz && rm -f /tmp/go.tar.gz
  ENV GOROOT $HOME/go
  ENV GOPATH $HOME/gopath
  ENV PATH $PATH:$GOROOT/bin:$GOPATH/bin:$HOME/bin
  
  RUN mkdir -p $HOME/restic
  
  # pre-install tools, this speeds up running the tests itself
  RUN go get github.com/constabulary/gb/...
  RUN go get golang.org/x/tools/cmd/cover
  RUN go get github.com/mattn/goveralls
  RUN go get github.com/mitchellh/gox
  