[CI] fix opam setup

Author: KihongHeo

.github/workflows/build.yml

@@ -22,7 +22,7 @@ jobs:
 
       - name: Build Claml
         run: |
-          ./build.sh
+          opam exec -- ./build.sh --user-opam-switch
 
-      - name: Run test (regression)
-        run: eval $(opam env) && make test
+      - name: Run test
+        run: opam exec -- make test

build.sh

@@ -7,22 +7,56 @@ export OPAMYES=1
 NCPU="$(getconf _NPROCESSORS_ONLN 2>/dev/null || echo 1)"
 OCAML_VERSION="5.1.0"
 CLAML_OPAM_SWITCH=claml-"$OCAML_VERSION+flambda"
-opam init --compiler=$OCAML_VERSION -j $NCPU --no-setup
 
-switch_exists=no
-for installed_switch in $(opam switch list --short); do
-  if [[ "$installed_switch" == "$CLAML_OPAM_SWITCH" ]]; then
-    switch_exists=yes
-    break
-  fi
+USER_OPAM_SWITCH=no
+
+function usage() {
+  echo "Usage: $0 [options]"
+  echo
+  echo " options:"
+  echo "   -h,--help             show this message"
+  echo "   --user-opam-switch    use the current opam switch to install haechi (default: $OPAM_SWITCH)"
+  echo
+  echo " examples:"
+  echo "    $0                     # build haechi with default options"
+  echo "    $0 --user-opam-switch  # build haechi in the current opam switch (e.g., for Github CI)"
+}
+
+while [[ $# -gt 0 ]]; do
+  opt_key="$1"
+  case $opt_key in
+    --user-opam-switch)
+      USER_OPAM_SWITCH=yes
+      shift
+      continue
+      ;;
+  esac
 done
-if [ "$switch_exists" = "no" ]; then
-  opam switch create $CLAML_OPAM_SWITCH $OCAML_VERSION
-else
-  opam switch $CLAML_OPAM_SWITCH
+
+function setup_opam() {
+  opam init --compiler=$OCAML_VERSION -j $NCPU --no-setup
+
+  switch_exists=no
+  for installed_switch in $(opam switch list --short); do
+    if [[ "$installed_switch" == "$CLAML_OPAM_SWITCH" ]]; then
+      switch_exists=yes
+      break
+    fi
+  done
+
+  if [ "$switch_exists" = "no" ]; then
+    opam switch create $CLAML_OPAM_SWITCH $OCAML_VERSION
+  else
+    opam switch $CLAML_OPAM_SWITCH
+  fi
+
+  eval $(SHELL=bash opam config env --switch=$CLAML_OPAM_SWITCH)
+}
+
+if [ "$USER_OPAM_SWITCH" == "no" ]; then
+  setup_opam
 fi
 
-eval $(SHELL=bash opam config env --switch=$CLAML_OPAM_SWITCH)
 opam pin add claml . -n
 opam install -j $NCPU claml --deps-only
 opam install ocamlformat.0.26.1