ISABELLE_USEDIR_OPTIONS: less ambitious -M1 by default -- multithreading is largely untested on fringe platforms (cygwin, solaris);
--- a/etc/settings Tue Apr 14 12:27:18 2009 +0200
+++ b/etc/settings Tue Apr 14 14:37:44 2009 +0200
@@ -90,7 +90,8 @@
### Batch sessions (cf. isabelle usedir)
###
-ISABELLE_USEDIR_OPTIONS="-M max -p 1 -v true -V outline=/proof,/ML"
+ISABELLE_USEDIR_OPTIONS="-M 1 -p 1 -v true -V outline=/proof,/ML"
+#ISABELLE_USEDIR_OPTIONS="-M max -p 1 -v true -V outline=/proof,/ML"
# Specifically for the HOL image
HOL_USEDIR_OPTIONS=""