From: Chris Marusich <cmmarus...@gmail.com>
Subject: Re: JARs and reference scanning
Date: Tue, 25 Apr 2017 22:34:02 -0700
I have to admit that I do not know at all how the reference
scanning and
dependency-tracking in the store works.
As I understand it, the mechanism used by the Guix daemon (and the
Nix
daemon) for scanning references doesn't work when the output of a
derivation is scrambled in some way (e.g. compressed). Therefore,
if we
use JAR files, they should not be compressed.
The code scanning for reference is in nix/libstore/references.cc .
It looks for base32 hashes encoded as character strings in the
binaries.
Could/should this be generalized somehow? Apart from compression,
store filenames encoded with 16-bit character encodings also cause
problems (can happen with Qt or WxWidgets). And the are probably
more cases where it fails.
Does it make sense to expand the reference detecting code (perhaps
this would lead to too many different special cases?), or maybe
provide a mechanism to force references when the daemon cannot detect
them. I suppose you can always add a text file with a list of store
items to the output, but maybe there's a more elegant way?
Thomas
