[ Filing this as a bug report, to not lose track of it. ]

Hi!

The attached untested patch should in principle do it. In any case the
available file is only ever up-to-date when using dselect, so this is
probably not a very generic solution. And if it's too slow, this should
be fixed in libdpkg-perl anyway as that would benefit every caller.

Thanks,
Guillem

Andy, Dam, what do you think about Guillem's patch?


Cheers,
gregor

-=| gregor herrmann, 23.03.2016 17:21:59 +0100 |=-

Seems to work (tests pass), but is noticeably slower:

 * without the patch
   dh-make-perl-dev --cpan Catalyst  29,33s user 2,30s system 94% cpu
   33,473 total
   (second try, after one dummy to fill CPAN/dh-make-perl caches)


 * with the patch
   dh-make-perl-dev --cpan Catalyst  233,96s user 3,13s system 99% cpu
   3:59,17 total

(both timings were on the gregoa/apt-file-3 branch)

Thanks for checking!

Ouch; 4 minutes seems a bit suboptimal :/

Ok, I guess this change won't make it into 0.90 in the current form
:)

Cheers,
gregor

A few years later … I tried again. After massaging the patch a bit to
apply against git master, I get, with the same methodology:

* without the patch: 169.02s user 22.11s system 112% cpu 2:49.26 total
* with the patch:    638.29s user 41.14s system 101% cpu 11:06.72 total

I guess that's still to slow :)


For posterity, I'm attaching the refreshed patch.


Cheers,
gregor

Hello,

Bug #808911 in dh-make-perl reported by you has been fixed in the
Git repository and is awaiting an upload. You can see the commit
message below and you can check the diff of the fix at:

https://salsa.debian.org/perl-team/modules/packages/dh-make-perl/-/commit/241d605f317089ec309b7dcac17707d052f2197e
------------------------------------------------------------------------
replace usage of DPKG::Parse::Available with Dpkg::Index

Closes: #808911

The slowdown that was observed in previous attemts was due to `if
($dpkg_available)` evaluating in string context causing stringification of
the whole index (≈6s per dependency)
------------------------------------------------------------------------

(this message was generated automatically)
-- 
Greetings

https://bugs.debian.org/808911

We believe that the bug you reported is fixed in the latest version of
dh-make-perl, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 808911@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Damyan Ivanov <dmn@debian.org> (supplier of updated dh-make-perl package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Fri, 10 Jun 2022 15:56:16 +0000
Source: dh-make-perl
Architecture: source
Version: 0.120
Distribution: unstable
Urgency: medium
Maintainer: Debian Perl Group <pkg-perl-maintainers@lists.alioth.debian.org>
Changed-By: Damyan Ivanov <dmn@debian.org>
Closes: 808911
Changes:
 dh-make-perl (0.120) unstable; urgency=medium
 .
   [ Damyan Ivanov ]
   * replace usage of DPKG::Parse::Available with Dpkg::Index.
     (Closes: #808911)
   * move the slow check for locally installed packages after the APT contents
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   * add automatic annotation of B-D with <!nocheck>. guarded with
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