automake: a millisecond is too fast for subsecond-mtime.

This patch is from https://bugs.gnu.org/68325.

* m4/sanity.m4 (_AM_FILESYSTEM_TIMESTAMP_RESOLUTION): don't try
for a millisecond; make a hundredth of a second the fastest we'll go.

Apparently there are plenty of systems which supposedly support
subsecond-mtimes down to the millisecond and yet randomly
fail parallelized tests. For example:
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=68119#18
Maybe the tests themselves need fixing. (The ones that run
autotools multiple times in succession.) A work in progress.

diff --git a/m4/sanity.m4 b/m4/sanity.m4
index 84fdf2d080f86952ed7cbbc7acd4a1e090e536f2..59afa7b152ac1d37be24c080e2e1bab45922e2a1 100644 (file)
--- a/m4/sanity.m4
+++ b/m4/sanity.m4
@@ -34,7 +34,7 @@ am_cv_filesystem_timestamp_resolution=2
 # Only try to go finer than 1s if sleep can do it.
 am_try_resolutions=1
 if $am_cv_sleep_fractional_seconds; then
-  am_try_resolutions="0.001 0.01 0.1 $am_try_resolutions"
+  am_try_resolutions="0.01 0.1 $am_try_resolutions"
 fi
 
 # In order to catch current-generation FAT out, we must *modify* files