Re: Modification date of /gnu/store files is 1970-01-01

2020-10-21 Thread John Soo
 Good to have you! 

 
A mention and description of purely functional package management ideas I think 
would be very welcome in the documentation.
 

 
Good luck,
 

 
John
 


Re: Modification date of /gnu/store files is 1970-01-01

2020-10-21 Thread Martin Michel
Tobias, John,

thank you for this explanation!  My first thought was… oh, something
broke during my installation.  But I was only spoiled by not resetting
my mind from the usual suspicious package managers.  Next time I will
think more about the nature of using a purely functional system, of
course it makes sense.

Do you think it is worth to spend a sentence about this in the
documentation (I must have skipped this if it is already there)?

And, by the way, thank you for the warm welcome!  I fully believe in
the concept and philosophy, so count me as a new user, ready to stay.

Kind regards,
Martin



Re: Modification date of /gnu/store files is 1970-01-01

2020-10-21 Thread John Soo
 Hello and welcome Martin! 

 
The Unix time stamp is set to 0 for one thing to ensure reproducible builds. If 
two build artifacts suffered in time stamps, they would be considered different.
 

 
Hope you find guix helpful and hackable,
 

 
John
 


Re: Modification date of /gnu/store files is 1970-01-01

2020-10-21 Thread John Soo
 Oops s/suffered/differed 


Re: Modification date of /gnu/store files is 1970-01-01

2020-10-21 Thread Tobias Geerinckx-Rice

Martin,

Martin Michel 写道:
So far so good, but I could not figure out what is wrong with 
the file system entries of /gnu/store.  All entries there have a 
timestamp of UNIX epoch 0.


Well spotted!  This is intentional.  The Guix daemon[0] changes 
all timestamps of all files added to the store to a known value. 
Same for other metadata like ownership and some permission bits.


If it did not, certain software could (and does) behave 
differently between two different machines with otherwise 
identical stores.


Kind regards,

T G-R

[0]: Inherited from Nix and still in C++: 
http://git.savannah.gnu.org/cgit/guix.git/tree/nix/libstore/local-store.hh#n293


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Re: Modification date of /gnu/store files is 1970-01-01

2020-10-21 Thread Wiktor Żelazny
On Wed, Oct 21, 2020 at 05:53:55PM +0200, Martin Michel wrote:

> All entries there have a timestamp of UNIX epoch 0.

Hello,

To my knowledge, this is intentional, and related to software
reproducibility.

Why do you find it problematic?

WŻ


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