Protocol buffers version mismatch in qt on macOS #14751

Trying to ./configure and then make. Getting

./qt/paymentrequest.pb.h:17:2: error: This file was generated by an older version of protoc which is
#error This file was generated by an older version of protoc which is
 ^
./qt/paymentrequest.pb.h:18:2: error: incompatible with your Protocol Buffer headers. Please
#error incompatible with your Protocol Buffer headers.  Please
 ^
./qt/paymentrequest.pb.h:19:2: error: regenerate this file with a newer version of protoc.
#error regenerate this file with a newer version of protoc.
 ^
./qt/paymentrequest.pb.h:131:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:131:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:259:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:259:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:465:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:465:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:648:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:648:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:771:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:771:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:943:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:943:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
15 errors generated.
make[2]: *** [qt/libbitcoinqt_a-bitcoingui.o] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from qt/guiutil.cpp:10:
In file included from ./qt/walletmodel.h:18:
In file included from ./qt/paymentrequestplus.h:10:
./qt/paymentrequest.pb.h:17:2: error: This file was generated by an older version of protoc which is
#error This file was generated by an older version of protoc which is
 ^
./qt/paymentrequest.pb.h:18:2: error: incompatible with your Protocol Buffer headers. Please
#error incompatible with your Protocol Buffer headers.  Please
 ^
./qt/paymentrequest.pb.h:19:2: error: regenerate this file with a newer version of protoc.
#error regenerate this file with a newer version of protoc.
 ^
./qt/paymentrequest.pb.h:131:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:131:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:259:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:259:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:465:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:465:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:648:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:648:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:771:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:771:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^
./qt/paymentrequest.pb.h:943:10: error: unknown type name 'PROTOBUF_CONSTEXPR'
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
         ^
./qt/paymentrequest.pb.h:943:29: error: expected member name or ';' after declaration specifiers
  static PROTOBUF_CONSTEXPR int const kIndexInFileMessages =
  ~~~~~~~~~~~~~~~~~~~~~~~~~ ^

Relevant / Helpful info:

protoc --version
libprotoc 3.6.1

Build works just fine if I add the NO_QT flag (which I guess is expected since the protobuf thing is in qt)

Try a ‘make clean’, and re-run autogen, configure and make.

Thanks @fanquake! I was confused reading the error log, maybe if something like

error: This file was generated by an older version of protoc or generated long ago. Please run make clean to start again

was printed, would've be more explanative. Thanks and sorry!