ARROW-7733: [Developer] Download new enough Go locally in release ver…

…ification script

Some developers have failed to run the Go part of the verification script because the version of Go required is newer than what is installed by some Linux package managers, such as Ubuntu 18.04

This also fixes the pesky need to write `TEST_DEFAULT=0 TEST_SOURCE=1 ... source $VERSION $RC_NUM` when `TEST_SOURCE=1` is redundant with the `source` mode. Additionally miniconda is only installed when it is needed by one of the verification steps

Closes #6710 from wesm/ARROW-7733

Authored-by: Wes McKinney <wesm+git@apache.org>
Signed-off-by: Wes McKinney <wesm+git@apache.org>

dev/release/verify-release-candidate.sh

@@ -456,10 +456,31 @@ test_ruby() {
 }
 
 test_go() {
+  local VERSION=1.14.1
+  local ARCH=amd64
+
+  if [ "$(uname)" == "Darwin" ]; then
+    local OS=darwin
+  else
+    local OS=linux
+  fi
+
+  local GO_ARCHIVE=go$VERSION.$OS-$ARCH.tar.gz
+  wget https://dl.google.com/go/$GO_ARCHIVE
+
+  mkdir -p local-go
+  tar -xzf $GO_ARCHIVE -C local-go
+  rm -f $GO_ARCHIVE
+
+  export GOROOT=`pwd`/local-go/go
+  export GOPATH=`pwd`/local-go/gopath
+  export PATH=$GOROOT/bin:$GOPATH/bin:$PATH
+
   pushd go/arrow
 
   go get -v ./...
   go test ./...
+  go clean -modcache
 
   popd
 }
@@ -705,8 +726,11 @@ test_wheels() {
 # By default test all functionalities.
 # To deactivate one test, deactivate the test and all of its dependents
 # To explicitly select one test, set TEST_DEFAULT=0 TEST_X=1
+if [ "${ARTIFACT}" == "source" ]; then
+  TEST_SOURCE=1
+fi
+
 : ${TEST_DEFAULT:=1}
-: ${TEST_SOURCE:=${TEST_DEFAULT}}
 : ${TEST_JAVA:=${TEST_DEFAULT}}
 : ${TEST_CPP:=${TEST_DEFAULT}}
 : ${TEST_CSHARP:=${TEST_DEFAULT}}
@@ -735,6 +759,14 @@ TEST_JS=$((${TEST_JS} + ${TEST_INTEGRATION_JS}))
 TEST_GO=$((${TEST_GO} + ${TEST_INTEGRATION_GO}))
 TEST_INTEGRATION=$((${TEST_INTEGRATION} + ${TEST_INTEGRATION_CPP} + ${TEST_INTEGRATION_JAVA} + ${TEST_INTEGRATION_JS} + ${TEST_INTEGRATION_GO}))
 
+if [ "${ARTIFACT}" == "wheels" ]; then
+  TEST_WHEELS=1
+else
+  TEST_WHEELS=0
+fi
+
+NEED_MINICONDA=$((${TEST_CPP} + ${TEST_WHEELS} + ${TEST_INTEGRATION}))
+
 : ${TEST_ARCHIVE:=apache-arrow-${VERSION}.tar.gz}
 case "${TEST_ARCHIVE}" in
   /*)
@@ -750,8 +782,10 @@ setup_tempdir "arrow-${VERSION}"
 echo "Working in sandbox ${TMPDIR}"
 cd ${TMPDIR}
 
-setup_miniconda
-echo "Using miniconda environment ${MINICONDA}"
+if [ ${NEED_MINICONDA} -gt 0 ]; then
+  setup_miniconda
+  echo "Using miniconda environment ${MINICONDA}"
+fi
 
 if [ "${ARTIFACT}" == "source" ]; then
   dist_name="apache-arrow-${VERSION}"
@@ -762,7 +796,7 @@ if [ "${ARTIFACT}" == "source" ]; then
   else
     mkdir -p ${dist_name}
     if [ ! -f ${TEST_ARCHIVE} ]; then
-      echo "${TEST_ARCHIVE} not found, did you mean to pass TEST_SOURCE=1?"
+      echo "${TEST_ARCHIVE} not found"
       exit 1
     fi
     tar xf ${TEST_ARCHIVE} -C ${dist_name} --strip-components=1