Reason: The machine file system time and time inconsistency
Solution: update all the files after recompiling
find . -type f | xargs -n 5 touch make clean make
xargs -n num adding times later, indicates the number of commands executed at the time of the argument once with default is all.
touch-free option, it will also update the file modification time and access time
supplement:
find . -exec touch {} \;
find command to match the file transfer command to the xargs, and xargs command each get only part of the file, but not all, unlike the -exec option that. So that it can first deal with the first part of the file retrieved, and then the next batch, and so continue.
In some systems, using -exec option to process each matching file to initiate a corresponding process is not matched to the file all at once executed as a parameter; so in some cases there will be too many processes, system performance degradation problems, which is not efficient;
http://blog.csdn.net/zhangfn2011/article/details/6776925/