Re: `make dep' with clock skew detected loops forever

[Michal Marek]

On 29.2.2012 20:01, Nishanth Aravamudan wrote:
> Noticed something on a fresh FC16 based install on a test server in our
> lab.  Autotest by default runs `make dep` and it seems the clock is
> pretty badly skewed on this server, resulting in an infinite loop of:
> 
> 01:09:37 DEBUG| Running 'make dep'
> 01:09:38 DEBUG| [stderr] make: Warning: File `/usr/local/autotest/tmp/build/linux/arch/powerpc/Makefile' has modification time 112143 s in the future
> 01:09:38 DEBUG| [stderr] make[1]: Warning: File `/usr/local/autotest/tmp/build/linux/arch/powerpc/Makefile' has modification time 112143 s in the future
> 01:09:38 DEBUG| [stderr] make[2]: Warning: File `scripts/Makefile.host' has modification time 112143 s in the future
> 01:09:38 DEBUG| [stdout]   HOSTCC  scripts/basic/fixdep
> 01:09:38 DEBUG| [stderr] make[2]: warning:  Clock skew detected.  Your build may be incomplete.
> 01:09:38 DEBUG| [stderr] make[2]: Warning: File `scripts/Makefile.host' has modification time 112143 s in the future
[...]

> Anyone know why that happens?

Because the system time time is several hours, if not days, behind, so
generated files are older than source files and thus dependencies cannot
work. You need to fix the system time to be at least ahead of the mtime
of the sources.


> Obvious fixes are to either not run `make dep`

I don't think this is limited to make dep.

Michal
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