diff -r 3cc075052033 -r d5ef492dd673 src/Pure/ML/ml_statistics.scala
--- a/src/Pure/ML/ml_statistics.scala	Wed Apr 09 17:40:27 2025 +0200
+++ b/src/Pure/ML/ml_statistics.scala	Wed Apr 09 22:23:59 2025 +0200
@@ -57,8 +57,7 @@
       if (props.nonEmpty) consume(props)
     }
 
-    val env_prefix =
-      if_proper(stats_dir, "export POLYSTATSDIR=" + Bash.string(stats_dir) + "\n")
+    val env_prefix = if_proper(stats_dir, Bash.exports("POLYSTATSDIR=" + stats_dir))
 
     Bash.process(env_prefix + "\"$POLYML_EXE\" -q --use src/Pure/ML/ml_statistics.ML --eval " +
         Bash.string("ML_Statistics.monitor " + ML_Syntax.print_long(pid) + " " +