add debug info

test is passing on my local machine; need to figure out how CI differs

examples/env_locations/build.rs

@@ -1,4 +1,15 @@
 fn main() {
+    println!("data path is {:?}", env!("GENERATED_DATA"));
+    println!("cwd is {:?}", std::env::current_dir());
+    println!(
+        "files in cwd: {:?}",
+        std::fs::read_dir(".").unwrap().collect::<Vec<_>>()
+    );
+    println!(
+        "files in parent: {:?}",
+        std::fs::read_dir("..").unwrap().collect::<Vec<_>>()
+    );
+
     let generated_data = std::fs::read_to_string(env!("GENERATED_DATA")).unwrap();
     // our generated data file should be readable
     assert_eq!(generated_data, "hello\n");