Don't clean version

1 files changed, 7 insertions, 2 deletions

diff --git a/buildfile b/buildfile
index 4e098b2..00e013f 100644
--- a/buildfile
+++ b/buildfile
@@ -4,8 +4,13 @@
 
 ./: tests/ doc{INSTALL LICENSE NEWS README version} file{manifest}
 
-doc{version}: file{manifest} # Generated by the version module.
-doc{version}: dist = true
+# The version file is auto-generated (by the version module) from manifest.
+# Include it in distribution and don't remove when cleaning in src (so that
+# clean results in a state identical to distributed).
+#
+doc{version}: file{manifest}
+doc{version}: dist  = true
+doc{version}: clean = ($src_root != $out_root)
 
 # Don't install tests or the INSTALL file.
 #