src/Pure/Thy/sessions.scala

--- a/src/Pure/Thy/sessions.scala	Mon Dec 26 16:44:13 2022 +0100
+++ b/src/Pure/Thy/sessions.scala	Mon Dec 26 16:57:07 2022 +0100
@@ -643,7 +643,7 @@
         if File.is_bib(file.file_name)
       } yield {
         val path = dir + document_dir + file
-        Bibtex.Entries.parse(File.read(path))
+        Bibtex.Entries.parse(File.read(path), file_pos = path.expand.implode)
       }).foldRight(Bibtex.Entries.empty)(_ ::: _)
 
     def record_proofs: Boolean = options.int("record_proofs") >= 2