Properly export LIBCLANG_PATH

This was previously reported in #5.

.github/workflows/ci.yaml

@@ -17,3 +17,5 @@ jobs:
           default: true
           ldproxy: false
       - run: rustc --print target-list | grep xtensa
+      - run: env | grep LIBCLANG_PATH
+      - run: xtensa-esp32-elf-gcc --version

install.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-set -e
+set -eu
 
 
 RE_VERSION="^[0-9]+\.[0-9]+\.[0-9]+(\.[0-9]+)?$"
@@ -57,3 +57,4 @@ esac
 #shellcheck source=/dev/null
 source "$HOME/exports"
 echo "$PATH" >> "$GITHUB_PATH"
+echo "LIBCLANG_PATH=${LIBCLANG_PATH}" >> "$GITHUB_ENV"