Enabling -ffile-prefix-map by default

[Lucas Nussbaum]

Hi Vagrant,

On 30/08/20 at 19:15 -0700, Vagrant Cascadian wrote:
> Hi Lucas!
> 
> I've appreciated all the work you've been doing with archive-wide
> rebuilds of Debian over the years!
> 
> I'm looking into proposing to enable dpkg's
> DEB_BUILD_OPTIONS=reproducible=+fixfilepath by default, further
> background in this thread:
> 
>   https://alioth-lists.debian.net/pipermail/reproducible-builds/Week-of-Mon-20200601/012375.html
> 
> We would like to figure out how many packages it causes to FTBFS
> (usually test suites expecting full paths); we've identified a small
> handful through tests.reproducible-builds.org:
> 
>   https://tests.reproducible-builds.org/debian/issues/bullseye/ftbfs_due_to_f-file-prefix-map_issue.html
>   https://tests.reproducible-builds.org/debian/issues/bullseye/ffile_prefix_map_passed_to_clang_issue.html
> 
> Those issues were identified through manually checking the build logs,
> and our reproducible builds infrastructure is not great for isolating
> out the effects of specific changes as each build has several variations
> tested.
> 
> It would be nice to try an archive-wide rebuild with +fixfilepath
> enabled and on failure,

Could you provide a dpkg package in a private repo (or in experimental)
with that enabled by default? And ideally a script similar to
https://salsa.debian.org/lucas/collab-qa-tools/-/blob/master/modes/gcc10
to install that package?

> automatically retry with -fixfilepath

That would be the current default, right? So a rebuild with vanilla
unstable would work as well?

> , so that
> we can flag which packages build fine without too much worry about false
> positives and in an automated fashion.
> 
> 
> I've never experimented with anything on an archive-wide scale before,
> so would appreciate any ideas, tooling or other help you might be able
> to offer. Thanks!

- Lucas
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://alioth-lists.debian.net/pipermail/reproducible-builds/attachments/20200831/2e7cc35e/attachment.sig>