Hi,

The dockerfile contains:

# Build the thing.
# Also: fix getting HEAD commit hash via git rev-parse.
RUN cd $SRC_DIR \
  && mkdir .git/objects \
  && make build GOTAGS=openssl IPFS_PLUGINS=$IPFS_PLUGINS

The line && mkdir .git/objects \ fails when this repository was obtained using the download zip function in github. As in that case the .git folder won't exist thus mkdir fails as it would need to create 2 directories.

There are 2 potential fixes here.

1. Just get rid of the line. Nothing seems to be dependent on it.
2. Change it to: && mkdir -p .git/objects \ (note the -p) to make it work as intended.

I locally changed this to -p which made the build work.

Cheers,
Mark