"git commit" seems to break the transaction interface about datakit HOT 4 CLOSED

cat <<EOT > test-datakit.sh
#!/bin/sh

DB=${DB:-/Applications/Docker.app/Contents/MacOS/com.docker.db}
DATAKIT=${DATAKIT:-${HOME}/go/src/github.com/moby/datakit/api/go-datakit}

if [ ! -e "${DB}" ]; then
  echo "Datakit binary not found at ${DB}: please set DB environment variable"
  exit 1
fi
if [ ! -e "${DATAKIT}" ]; then
  echo "Datakit source tree not found at "${DATAKIT}". Note it has to be on the GOPATH".
  exit 1
fi

echo Using datakit from: "${DB}"
echo Using test cases from source tree: "${DATAKIT}"

database=$(mktemp -d)
echo Created temporary database dir "${database}"

DB_PID=0
TEST_PID=0
clean_up () {
    rm -rf "${database}"
    kill "${DB_PID}" 2> /dev/null
    kill "${TEST_PID}" 2> /dev/null
}

trap clean_up EXIT

pushd "${database}"
git init .
echo foo > bar
git add bar
git commit bar -m test
popd

"${DB}" --git "${database}" --url file:///var/tmp/foo&
DB_PID=$!

sleep 1 # easier than performing fd passing in a shell script

cd "${DATAKIT}"
go test -run TestTransaction 2>/dev/null >/dev/null &
TEST_PID=$!

retries=5
while [ "${retries}" -ne 0 ]; do
  if kill -0 "${TEST_PID}" 2> /dev/null; then
    echo Test is still running
    retries=$(( retries - 1 ))
    sleep 1
  else
    echo Test has finished
    echo Success
    exit 0
  fi
done

echo Test has timed out
echo Failure
exit 1
EOT

$ ./test-datakit.sh 
Using datakit from: /Applications/Docker.app/Contents/MacOS/com.docker.db
Using test cases from source tree: /Users/djs/go/src/github.com/moby/datakit/api/go-datakit
Created temporary database dir /var/folders/5q/xqlk9dzn5jz7_hn2j31brc0r0000gn/T/tmp.M04AzKw9
/var/folders/5q/xqlk9dzn5jz7_hn2j31brc0r0000gn/T/tmp.M04AzKw9 ~
Initialized empty Git repository in /private/var/folders/5q/xqlk9dzn5jz7_hn2j31brc0r0000gn/T/tmp.M04AzKw9/.git/
[master (root-commit) af2828f] test
 1 file changed, 1 insertion(+)
 create mode 100644 bar
~
Starting com.docker.db 0.7.0-34-g6f04213 ...
Test is still running
com.docker.db: [INFO] accepted a new connection on file:///var/tmp/foo
com.docker.db: [INFO] Using protocol TwoThousand msize 16384
Test has finished
Success

DB=~/go/src/github.com/docker/pinata/mac/build/Docker.app/Contents/MacOS/com.docker.db ./test-datakit.sh 
Using datakit from: /Users/djs/go/src/github.com/docker/pinata/mac/build/Docker.app/Contents/MacOS/com.docker.db
Using test cases from source tree: /Users/djs/go/src/github.com/moby/datakit/api/go-datakit
Created temporary database dir /var/folders/5q/xqlk9dzn5jz7_hn2j31brc0r0000gn/T/tmp.mRISPXGH
/var/folders/5q/xqlk9dzn5jz7_hn2j31brc0r0000gn/T/tmp.mRISPXGH ~
Initialized empty Git repository in /private/var/folders/5q/xqlk9dzn5jz7_hn2j31brc0r0000gn/T/tmp.mRISPXGH/.git/
[master (root-commit) 692e305] test
 1 file changed, 1 insertion(+)
 create mode 100644 bar
~
Starting com.docker.db %%VERSION%% ...
Test is still running
com.docker.db: [INFO] accepted a new connection on file:///var/tmp/foo
com.docker.db: [INFO] Using protocol TwoThousand msize 16384
Test is still running
Test is still running
Test is still running
Test is still running
Test has timed out
Failure
com.docker.db: [ERROR] Uncaught exception handling tag 72 Write(fid: 126, offset: 0, len(data): 6): 
                       Exception: (Sys_error
  "/var/folders/5q/xqlk9dzn5jz7_hn2j31brc0r0000gn/T/tmp.mRISPXGH/.git/lock/refs/heads: No such file or directory")
                       No backtrace available.