The rebuild of protobuf no longer has lto information according to objdump, but the reported version certainly does. The "bad" version was built during hirsute devel, so I took a current hirsute system and systematically downgraded build-deps to the versions in the log of the "bad" build. Turns out, the relevant difference is a couple libs from elfutils: libdw1 and libelf1. If I build protobuf w/ the 0.183-6 versions, I can reproduce the problem. 0.183-8 does not (0.183-7 FTBFS, so could not be tested).
Strangely the delta between elfutils 0.183-6 and 0.183-8 appears innocuous - it all looks like packaging cleanup, no changes to upstream source.
The rebuild of protobuf no longer has lto information according to objdump, but the reported version certainly does. The "bad" version was built during hirsute devel, so I took a current hirsute system and systematically downgraded build-deps to the versions in the log of the "bad" build. Turns out, the relevant difference is a couple libs from elfutils: libdw1 and libelf1. If I build protobuf w/ the 0.183-6 versions, I can reproduce the problem. 0.183-8 does not (0.183-7 FTBFS, so could not be tested).
Strangely the delta between elfutils 0.183-6 and 0.183-8 appears innocuous - it all looks like packaging cleanup, no changes to upstream source.