Ah, I see the thread for https://issues.guix.gnu.org/47614 wasn't cc'ed
here:
-------- Forwarded Message --------
Subject: Re: Racket 8 and store references (was [security] Chunked store
references in .zo files in Racket 8 #47614)
Date: Tue, 6 Apr 2021 21:38:57 -0400
From: Philip McGrath <phi...@philipmcgrath.com>
To: Jack Hill <jackh...@jackhill.us>, Mark H Weaver <m...@netris.org>
CC: guix-de...@gnu.org
Indeed, I expect this is a more precise diagnosis of the same problem.
My patch in https://issues.guix.gnu.org/47180 solves it by putting the
store references (search paths for foreign libraries) in a configuration
data file that isn't compiled, so they don't end up in .zo files in the
first place.
The .zo format is intentionally undocumented and subject to breaking
change, including from different compilation options. At a minimum, a
change to the Racket version number signals a breaking change to
compiled code (e.g. Git is now at 8.0.0.13, so 13 breaking changes since
the release). Internally, I don't know all the details, but the normal
8.0 .zo format has a Racket layer around the Chez Scheme object format,
which seems to be very complex: it looks like it supports
user-configurable compression at the granularity of the individual
object within an object file. So it seems much better to avoid rewriting
.zo files altogether.
-Philip
On 4/6/21 9:20 PM, Jack Hill wrote:
On Tue, 6 Apr 2021, Mark H Weaver wrote:
Anyway, I doubt that imposing such a limitation would adequately solve
the problem here of chunked references in Racket 8, because I suspect
that Racket 8 could split store references at arbitrary points in the
string. I doubt that we can safely assume that the hash component of
store references will be stored contiguously in *.zo files.
Mark and everyone,
I wanted to spin off a subthread on guix-devel, to make you aware of
another problem that we've run into with reference in .zo getting
mangled: https://issues.guix.gnu.org/47180
Best,
Jack
