Toggle quote (23 lines)
> Hi again Andrew,
>
> It turns out that the package is not reproducible:
>
> --8<---------------cut here---------------start------------->8---
> $ ./pre-inst-env guix challenge scheme48-prescheme
> /gnu/store/qkby7f4nr3lxlm16zmswmka5hgfs6spw-scheme48-prescheme-1.9.2 contents differ:
> no local build for '/gnu/store/qkby7f4nr3lxlm16zmswmka5hgfs6spw-scheme48-prescheme-1.9.2'
> https://ci.guix.gnu.org/nar/lzip/qkby7f4nr3lxlm16zmswmka5hgfs6spw-scheme48-prescheme-1.9.2: 0fahr4s5qz980zz96xmrwf8r87w56kicxr8s80fvis98q7v5czll
> https://bordeaux.guix.gnu.org/nar/lzip/qkby7f4nr3lxlm16zmswmka5hgfs6spw-scheme48-prescheme-1.9.2: 0jphmcmijk68phwq93qbzszy5pdmnasa3qdcp2nc5wqc25a7kpxk
> differing file:
> /lib/scheme48-1.9.2/prescheme.image
>
> 1 store items were analyzed:
> - 0 (0.0%) were identical
> - 1 (100.0%) differed
> - 0 (0.0%) were inconclusive
> $ git log |head -1
> commit cf9e0508b26196dc985302776d860a0359652c59
> --8<---------------cut here---------------end--------------->8---
>
> Any idea what might be wrong?
Hmm, interesting!
This is an image produced by Scheme 48 dumping its VM state into a file
which can be loaded later to save parsing/expansion time. This is the
same technique used by Scheme 48 to produce its own initial image. It
looks like the "scheme48" package has the same problem:
```
$ guix challenge scheme48
/gnu/store/9c47l5cn60zrr9sm0hn55zibf8zmv33l-scheme48-1.9.2 contents differ:
local hash: 0pyygj4nf8fw2xpciy81d01r2b2339bxhgpfdn2zq2wqvsn2ycra
0pyygj4nf8fw2xpciy81d01r2b2339bxhgpfdn2zq2wqvsn2ycra
12wxxqxmpdqgg2fzbcbm68h1jqynz9gqhxzalyspqq7hh2fgr46k
differing file:
/lib/scheme48-1.9.2/scheme48.image
1 store items were analyzed:
- 0 (0.0%) were identical
- 1 (100.0%) differed
- 0 (0.0%) were inconclusive
```
Comparing hex dumps of the files, there are significant differences, and
a quick dive through the image dumping code leads into VM and garbage
collector details which are over my head.
I guess patching Scheme 48 to build deterministic images is out-of-scope
and maybe an issue for upstream.
Toggle quote (3 lines)
> Thanks,
> Ludo’.
