Re: How to debug / investigate non-reproducible build for r-repr?

[Brice Waegeneire <brice@waegenei.re>]

Hello Peter,

On 2020-06-29 08:25, Lo Peter wrote:
> I am trying to import r-languageserver, and one of its dependency is
> r-repr, which I found that cannot be built reproducibly (on my
> laptop's guix, installed on Linux Mint), i.e.
> 
>         guix build --rounds=2 r-repr
> 
> would give the error saying that "...r-repr-1.1.0.drv differs from
> previous round".
> 
> How should I begin to investigate the issue?

I'm new to fixing non reproductible build, all I ever needed thus
far is using 'diffoscope'.  Note that this program has a lot of
optional dependencies that aren't installed by default but you
get a warning when 'diffoscope' can make uses of such dependencies,
in the case of 'r-repr' it wants to use 'Rscript'.

Here is quick use of it:
--8<---------------cut here---------------start------------->8---
$ guix environment --ad-hoc diffoscope r
$ guix build r-repr --check --keep-failed
…
guix build: error: derivation 
`/gnu/store/5rbf3kb0s96m1nij5s631j1k3mnh75lg-r-repr-1.1.0.drv' may not 
be deterministic: output 
`/gnu/store/aah5bpxg1h3sf09ca1plp4cbj745n95y-r-repr-1.1.0' differs from 
‘/gnu/store/aah5bpxg1h3sf09ca1plp4cbj745n95y-r-repr-1.1.0-check’
$ diffoscope --exclude-command stat 
/gnu/store/aah5bpxg1h3sf09ca1plp4cbj745n95y-r-repr-1.1.0{,-check}
--8<---------------cut here---------------end--------------->8---

- Brice