FTBFS on hppa: DBus.QueryingUnixProcessIdReturnsCorrectResult fails

[lamby]

via https://bugs.debian.org/888996:

The build of dbus-cpp for hppa (admittedly not a release architecture)
failed as detailed below. Could you please take a look?

Thanks!

----------------------------------------------------------------------

 3/15 Test #4: dbus_test ........................***Failed 0.56 sec
Running main() from gmock_main.cc
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from DBus
[ RUN ] DBus.QueryingUnixProcessIdReturnsCorrectResult
dbus[6265]: Attempted to unregister path (path[0] = this path[1] = is) which isn't registered
core::posix::fork(): An unhandled std::exception occured in the child process:
  what(): org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
   0@ 0xfd70b7f0: [0xfd70b7f0]
   1@ 0xfd70b920: [0xfd70b920]
terminate called after throwing an instance of 'std::runtime_error'
  what(): org.freedesktop.DBus.Error.NameHasNoOwner: Could not get PID of name ':1.1': no such name
/<<BUILDDIR>>/dbus-cpp-5.0.0+18.04.20171031/tests/dbus_test.cpp:123: Failure
      Expected: core::posix::exit::Status::success
      Which is: 4-byte object <00-00 00-00>
To be equal to: client_result.detail.if_exited.status
      Which is: 4-byte object <00-00 00-01>
/<<BUILDDIR>>/dbus-cpp-5.0.0+18.04.20171031/tests/dbus_test.cpp:129: Failure
      Expected: core::posix::wait::Result::Status::exited
      Which is: 4-byte object <00-00 00-02>
To be equal to: service_result.status
      Which is: 4-byte object <00-00 00-03>
/<<BUILDDIR>>/dbus-cpp-5.0.0+18.04.20171031/tests/dbus_test.cpp:131: Failure
      Expected: core::posix::exit::Status::success
      Which is: 4-byte object <00-00 00-00>
To be equal to: service_result.detail.if_exited.status
      Which is: 4-byte object <00-00 00-06>
[ FAILED ] DBus.QueryingUnixProcessIdReturnsCorrectResult (380 ms)
[----------] 1 test from DBus (380 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (380 ms total)
[ PASSED ] 0 tests.
[ FAILED ] 1 test, listed below:
[ FAILED ] DBus.QueryingUnixProcessIdReturnsCorrectResult

 1 FAILED TEST

[...]

93% tests passed, 1 tests failed out of 15

Total Test time (real) = 16.59 sec

The following tests FAILED:
   4 - dbus_test (Failed)
Errors while running CTest