# "Clock skew detected"? [SOLVED]

## BLWizard

Hi there.

I have just installed a fresh gentoo 2005.1 from stage3. 

When I run "make menuconfig" and "make" in the directory of kernel sources, it constantly warns me that"

warning: Clock skew detected. Your build may be imcomplete.

warning: File 'arch/i386/kernel/.vsyscal.o.cmd' has modification time 2e+04 s in the future

What does that mean and how can I fix it?

Thanks in advance

AndyLast edited by BLWizard on Tue Oct 04, 2005 6:15 pm; edited 1 time in total

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## frostschutz

make uses timestamp of files to find out which files it has to (re)compile. mechanisms such as this rely on a constant timeflow, e.g. timestamp (number in seconds since ...) increases steadily.

For some reason, some of your files have a bad timestamp (from the future, so somehow your time flowed backwards), so the mechanism doesn't work reliably any more, which may result in bad / incomplete builds.

The following may fix the issue, providing that timeflow is fixed and not constantly wrong due to bios / kernel bug:

```
# go to your kernel source directory

cd /usr/src/

# update timestamp of all files

find . -exec touch \{\} \;

# delete old compiled stuff

make clean

# compile from scratch

make bzImage modules_install or whatever
```

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## Raistlin

Hi,

this may also occur, if you map a directory with nfs and the server's is not in sync with the client's time...

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## BLWizard

Got the point. Thanks!

 *frostschutz wrote:*   

> make uses timestamp of files to find out which files it has to (re)compile. mechanisms such as this rely on a constant timeflow, e.g. timestamp (number in seconds since ...) increases steadily.
> 
> For some reason, some of your files have a bad timestamp (from the future, so somehow your time flowed backwards), so the mechanism doesn't work reliably any more, which may result in bad / incomplete builds.
> 
> The following may fix the issue, providing that timeflow is fixed and not constantly wrong due to bios / kernel bug:
> ...

 

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## Rukie

Hi, this post has helped me several times before, but now my find command doesn't work! After issuing the above command, I get an error saying "find: missing argument to '-exec'" Please help me.

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## pantokrator

Did you typed space between {\} and \; ?

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## Rukie

whoops, thanks  :Smile: 

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## atrus123

 *frostschutz wrote:*   

> 
> 
> ```
> # go to your kernel source directory
> 
> ...

 

Great post!  This fixed this problem for me as well.

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## cchildress

Are there any restrictions to running this command from / ?  Let's say that dual booting gentoo/windows without setting "local" in the clock config has caused skew in *many* files across the system.  Would simply running find . -exec touch \{\} \; from / break anything or cause problems?

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