build-setup: Use a slightly later ancient timestamp for dummy files.

GNU Make secretly reserves extreme-valued timestamps for its own
internal purposes, and then complains about `Timestamp out of range'.
This is annoying enough; but for some reason I don't understand, at
least on Cygwin, instead of substituting its most ancient acceptable
timestamp, it uses its furthest into the future stamp with the result
that it gets stuck in a loop rebuilding makefiles.

Using the second year of the epoch seems to fix the problem.

diff --git a/build-setup b/build-setup
index ded8b11..2bbf56f 100755 (executable)
--- a/build-setup
+++ b/build-setup
@@ -1,4 +1,4 @@
 #! /bin/sh -ex
 for gen in symm/modes.am symm/stubs.am; do
-  if [ ! -r $gen ]; then touch -t197001010000.00 $gen; fi
+  if [ ! -r $gen ]; then touch -t197101010000.00 $gen; fi
 done