Use latest coursier and sbt-coursier on CI

Seems older coursier versions frequently run into errors like

    C:\Users\...\AppData\Local\Coursier\cache\v1\.structure.lock (Access is denied)

scripts/ci.sh

@@ -1,6 +1,19 @@
 #!/usr/bin/env bash
 set -euvx
 
+./scripts/cs-setup.sh
+mkdir -p bin
+./cs bootstrap -o bin/sbt sbt-launcher io.get-coursier:coursier_2.12:2.0.0-RC6-25
+rm -f cs cs.exe
+
+if [ "$(expr substr $(uname -s) 1 5 2>/dev/null)" == "Linux" ]; then
+  SBT="./bin/sbt -C--plugin-version=2.0.0-RC6-8"
+elif [ "$(uname)" == "Darwin" ]; then
+  SBT="./bin/sbt -C--plugin-version=2.0.0-RC6-8"
+else
+  SBT="./bin/sbt.bat -C--plugin-version=2.0.0-RC6-8"
+fi
+
 lmCoursier() {
   [ "${PLUGIN:-""}" = "sbt-lm-coursier" ]
 }
@@ -15,7 +28,7 @@ runLmCoursierTests() {
   fi
 
   # publishing locally to ensure shading runs fine
-  ./metadata/scripts/with-test-repo.sh ./sbt \
+  ./metadata/scripts/with-test-repo.sh $SBT \
     evictionCheck \
     compatibilityCheck \
     lm-coursier-shaded/publishLocal \
@@ -32,7 +45,7 @@ runSbtCoursierTests() {
     SCRIPTED_EXTRA=""
   fi
 
-  ./metadata/scripts/with-test-repo.sh ./sbt \
+  ./metadata/scripts/with-test-repo.sh $SBT \
     sbt-coursier-shared/test \
     "sbt-coursier/scripted shared-$TEST_GROUP/* $SCRIPTED_EXTRA"
 }

scripts/cs-setup.sh

@@ -0,0 +1,105 @@
+#!/usr/bin/env bash
+
+#
+# coursier launcher setup script
+# See https://github.com/coursier/ci-scripts
+#
+
+
+set -e
+
+coursier_version="2.0.0-RC6-24"
+for_graalvm="false"
+dest="cs"
+
+# Adapted from https://github.com/paulp/sbt-extras/blob/ea47026bd55439760f4c5e9b27b002fa64a8b82f/sbt#L427-L435 and around
+die() {
+  echo "Aborting: $*"
+  exit 1
+}
+process_args() {
+  require_arg() {
+    local type="$1"
+    local opt="$2"
+    local arg="$3"
+
+    if [[ -z "$arg" ]] || [[ "${arg:0:1}" == "-" ]]; then
+      die "$opt requires <$type> argument"
+    fi
+  }
+  parsing_args="true"
+  while [[ $# -gt 0 && "$parsing_args" == "true" ]]; do
+    case "$1" in
+      --version) require_arg version "$1" "$2" && coursier_version="$2" && shift 2 ;;
+      --dest) require_arg path "$1" "$2" && dest="$2" && shift 2 ;;
+      --graalvm) for_graalvm="true" && shift ;;
+      *) die "Unexpected argument: '$1'" ;;
+    esac
+  done
+}
+
+process_args "$@"
+
+
+do_chmod="1"
+ext=""
+setenv_bat="0"
+
+# https://stackoverflow.com/questions/3466166/how-to-check-if-running-in-cygwin-mac-or-linux/17072017#17072017
+if [ "$(expr substr $(uname -s) 1 5 2>/dev/null)" == "Linux" ]; then
+  cs_url="https://github.com/coursier/coursier/releases/download/v$coursier_version/cs-x86_64-pc-linux"
+  cache_base="$HOME/.cache/coursier/v1"
+elif [ "$(uname)" == "Darwin" ]; then
+  cs_url="https://github.com/coursier/coursier/releases/download/v$coursier_version/cs-x86_64-apple-darwin"
+  cache_base="$HOME/Library/Caches/Coursier/v1"
+else
+  # assuming Windows…
+  cs_url="https://github.com/coursier/coursier/releases/download/v$coursier_version/cs-x86_64-pc-win32.exe"
+  cache_base="$LOCALAPPDATA/Coursier/v1" # TODO Check that
+  ext=".exe"
+  do_chmod="0"
+
+  if [ "$for_graalvm" = "true" ]; then
+    choco install -y windows-sdk-7.1 vcbuildtools kb2519277
+    setenv_bat="1"
+  fi
+fi
+
+cache_dest="$cache_base/$(echo "$cs_url" | sed 's@://@/@')"
+
+if [ -f "$cache_dest" ]; then
+  echo "Found $cache_dest in cache"
+else
+  mkdir -p "$(dirname "$cache_dest")"
+  tmp_dest="$cache_dest.tmp-setup"
+  echo "Downloading $cs_url"
+  curl -Lo "$tmp_dest" "$cs_url"
+  mv "$tmp_dest" "$cache_dest"
+fi
+
+if [ "$setenv_bat" = "1" ]; then
+  cp "$cache_dest" ".$dest$ext"
+  "./.$dest$ext" --help
+  if [ "$do_chmod" = "1" ]; then
+    chmod +x ".$dest$ext"
+  fi
+  cat > "$dest.bat" << EOF
+@call "C:\\Program Files\\Microsoft SDKs\\Windows\\v7.1\\Bin\\SetEnv.Cmd"
+%~dp0.$dest$ext %*
+EOF
+  # that one is for bash
+  cat > "$dest" << EOF
+#!/usr/bin/env bash
+set -e
+exec $(pwd)/$dest.bat "\$@"
+EOF
+  chmod +x "$dest" || true
+else
+  cp "$cache_dest" "$dest$ext"
+  if [ "$do_chmod" = "1" ]; then
+    chmod +x "$dest$ext"
+  fi
+fi
+
+export PATH=".:$PATH"
+"$dest" --help