Re: How long does it usually take to pull --no-substitutes?

[Steve George]

Hi,

On 20/05/2023 12:05, Zelphir Kaltstahl wrote:
> Hello Guix users!
>
> Recently I had an issue when I did a `guix pull`, so I tried `guix pull 
> --no-substitutes`. My understanding is, that substitutes are platform 
> specific pre-built binaries, which one can download from the guix 
> servers, instead of building them oneself. (Please correct me, if this 
> is wrong.) So I thought, that most time would be spent compiling things 
> and hopefully compiling many things in parallel as much as possible, to 
> speed up the whole process. However, guix seemed stuck at some "build 
> phase". I waited for like 2h or so, but it was still at that build 
> phase. Is this normal? How long does it usually take to run with no 
> substitutes? I guess it also depends on what one has in ones profile, so 
> here is my output of `guix pacakge -i`:

It will take a lot longer to download and build, rather than use 
substitutions.

Each package is built one after another, Guix doesn't build them in 
parallel AFAIK. If one of the packages in a transaction doesn't build 
then the transaction will fail unless you provide the `--keep-going` switch.

Sounds like one of the packages failed to build - so none of the 
packages were updated.

It should tell you right in the output which one is failing and give you 
a log.

How long it takes a package to compile depends on the size of the 
package, the capabilities of your system and how much of your system 
you've allowed Guix to use. I find the options for guix build --max-jobs 
very useful.

It's pretty variable how long things take: at one extreme Chromium takes 
over 10 hours to compile on my poor laptop!

When a build fails the easiest way to see what is happening is to view 
the log and go into the environment to see what's happening:

  $ guix build --no-substitutes --keep-failed <package>

The section on 'Debugging Build Failures' is particularly useful [0]

I generally do what you suggest and build the smallest subset of 
packages myself if there is no other choice (no substitute) - otherwise 
I'm just wasting resources - though building Chromium once was fun!

Best of luck,

Futurile

[0] https://guix.gnu.org/en/manual/en/guix.html#Debugging-Build-Failures