Looking for a way to cache .deb files downloaded by apt inside sbuild schroot

[Uladzimir Bely <ubely@ilbers.de>]

When sbuild is used to compile a package from sources, some packages (package 
dependencies) are internally downloaded and installed in schroot.

I'm looking for a way to cache the dependencies in form of .deb files outside 
the schroot. So that I could later create a local partial debian repo from 
these .deb files and run sbuild for a second time using the same schroot but 
with local repo for getting dependencies.

I tried several options for sbuild (like --purge-build=never, --purge-
deps=never, --purge-session=never), tried to find .deb files during the build 
using at some stages (--pre-build-commands="ls -la /var/cache/apt/archives/",  
--starting-build-commands="ls -la /var/cache/apt/archives/", --finished-build-
commands="ls -la /var/cache/apt/archives/") - but I couldn't see any .deb 
files inside the schroot.

-- 
Uladzimir Bely
Promwad Ltd.
External service provider of ilbers GmbH
Maria-Merian-Str. 8
85521 Ottobrunn, Germany
+49 (89) 122 67 24-0
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