Add FreeBSD CI test

.github/workflows/freebsd.yml

@@ -0,0 +1,32 @@
+name: Test
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    name: A job to run test in FreeBSD
+    env:
+      MYTOKEN : "lala"
+      MYTOKEN2: "value2"
+    steps:
+    - uses: actions/checkout@v4
+    - name: Test in FreeBSD
+      id: test
+      uses: vmactions/freebsd-vm@v1
+      with:
+        envs: 'MYTOKEN MYTOKEN2'
+        usesh: true
+        prepare: |
+          set -x
+          pkg install -y curl automake fltk
+
+        run: |
+          set -x
+          pwd
+          freebsd-version
+          ./autogen.sh
+          ./configure
+          make
+          make check
+          make distcheck

configure.ac

@@ -143,6 +143,13 @@ dnl -----------------------------------------------------------------
 dnl
 BASE_CUR_WORKING_DIR=`pwd`
 
+dnl ------------------------------------------
+dnl Add /usr/include before /usr/include/local
+dnl ------------------------------------------
+dnl
+CPPFLAGS="$CPPFLAGS -I/usr/include"
+LDFLAGS="$LDFLAGS -L/usr/lib"
+
 dnl --------------------------------------
 dnl Check whether to add /usr/local or not
 dnl (this is somewhat a religious problem)