[Pkg-xmpp-devel] Bug#1095353: libsignal-protocol-c: FTBFS: #error This file was generated by a newer version of protobuf-c which is incompatible with your libprotobuf-c headers.

[Stefan Kropp]

Maybe this is the reason of the bug:

( cd protobuf ; /usr/bin/make )
make[2]: Entering directory '/<<PKGBUILDDIR>>/protobuf'
protoc-c --c_out=../src/ WhisperTextProtocol.proto LocalStorageProtocol.proto FingerprintProtocol.proto
[libprotobuf WARNING protoc-gen-c/main.cc:44] `protoc-c` is deprecated. Please use `protoc` instead!
[libprotobuf WARNING google/protobuf/compiler/parser.cc:646] No syntax specified for the proto file: WhisperTextProtocol.proto. Please use 'syntax = "proto2";' or 'syntax = "proto3";' to specify a syntax version. (Defaulted to proto2 syntax.)
[libprotobuf WARNING google/protobuf/compiler/parser.cc:646] No syntax specified for the proto file: LocalStorageProtocol.proto. Please use 'syntax = "proto2";' or 'syntax = "proto3";' to specify a syntax version. (Defaulted to proto2 syntax.)
[libprotobuf WARNING google/protobuf/compiler/parser.cc:646] No syntax specified for the proto file: FingerprintProtocol.proto. Please use 'syntax = "proto2";' or 'syntax = "proto3";' to specify a syntax version. (Defaulted to proto2 syntax.)
make[2]: Leaving directory '/<<PKGBUILDDIR>>/protobuf'

May guess is, that those files are used to build the generated
files.

-- 
Stefan