X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=blobdiff_plain;f=README;h=fcf8c000f89a6ea61f92deca0a1aabaa420fce96;hp=bbec51884700b9776f8f9491f1b6375b0a9c1e0d;hb=2a8a5a4b83fa745c7016a68dad7722aed4709705;hpb=1b270f7465f5c94d8d47fd237c53dd9c827ed2c9

diff --git a/README b/README
index bbec518..fcf8c00 100644
--- a/README
+++ b/README
@@ -371,6 +371,13 @@ makefiles, you may find that just `make' is broken now and cannot get
 far enough to regenerate a working set of makefiles.  If this happens
 just rerun ./config.status by hand.
 
+If you go back and forth between different versions of your code you
+can sometimes find that `make' complains that one of your Subdir.sd.mk
+files is missing: typically, if iot was used and therefore a
+dependency in some other version of your code.  If you run `make
+clean' (or `make realclean') these dependencies are suppressed, which
+will clear up the problem.
+
 
 Legal information
 -----------------