remove output file on error

bipc/src/lib.rs

@@ -61,7 +61,10 @@ pub fn run(path: &str, outfile: &str) -> Result<()> {
 
     bp::Writer::new()
         .parse_tree(&node_tree)
-        .map_err(Error::BpError)?
+        .or_else(|e| {
+            std::fs::remove_file(outfile).map_err(Error::BadWrite)?;
+            Err(Error::BpError(e))
+        })?
         .write_to(&mut out)
         .map_err(Error::BadWrite)
 }