On Fri, Sep 11, 2026, at 2:22 PM, Sylvestre Ledru wrote: > Le 11/09/2026 à 14:16, Jochen Sprickerhof a écrit : >> >>> How can i work around this? >> >> By reverting the change. I am not aware of a way to make PGO >> reproducible. >> >> Note that reproduce.debian.net tries to reproduce the .deb that is >> distributed by Debian so we can't just disable it in the rebuild as it >> would still not be reproducible. >> > This means decreasing the performance by 20 to 40%...
this probably warrants some broader discussion.. I think the only way to implement PGO and reproduciblity is to treat the profiles as allowed generated input to the build (i.e., lift the restriction of "all pre-generated parts of the upstream source must be regenerated as part of the build" for them). then you could generate the profiles at upstream release time, and put them into the source package (or a second component tarball on the Debian side). since the profile is static (per upstream version), the PGO build should be reproducible then. I guess the same applies to a lot of other (a lot more complex) projects, e.g. AFAIK firefox and chromium upstream also heavily employ PGO, as does the Rust toolchain. Fabian
