Snapcraft crashing with elftools.common.exceptions.ELFError

Building the go snap fails in launchpad at the moment. The full log is at https://launchpadlibrarian.net/397050232/buildlog_snap_ubuntu_xenial_ppc64el_go-tip_BUILDING.txt.gz
but the last interesting bit is:

Sorry, an error occurred in Snapcraft:
We would appreciate it if you created a bug report at
https://launchpad.net/snapcraft/+filebug with the above text included.
Traceback (most recent call last):
  File "/usr/bin/snapcraft", line 9, in <module>
    load_entry_point('snapcraft==2.43.1', 'console_scripts', 'snapcraft')()
  File "/usr/lib/python3/dist-packages/click/core.py", line 716, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/click/core.py", line 696, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python3/dist-packages/click/core.py", line 1037, in invoke
    return Command.invoke(self, ctx)
  File "/usr/lib/python3/dist-packages/click/core.py", line 889, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python3/dist-packages/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/lib/python3/dist-packages/snapcraft/cli/_runner.py", line 93, in run
    ctx.forward(lifecyclecli.commands["snap"])
  File "/usr/lib/python3/dist-packages/click/core.py", line 552, in forward
    return self.invoke(cmd, **kwargs)
  File "/usr/lib/python3/dist-packages/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/snapcraft/cli/lifecycle.py", line 136, in snap
    project = _execute(steps.PRIME, parts=[], **kwargs)
  File "/usr/lib/python3/dist-packages/snapcraft/cli/lifecycle.py", line 35, in _execute
    lifecycle.execute(step, project_config, parts)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 90, in execute
    executor.run(step, part_names)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 194, in run
    self._handle_step(part_names, part, step, current_step, cli_config)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 208, in _handle_step
    getattr(self, "_run_{}".format(current_step.name))(part)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 283, in _run_prime
    self._run_step(step=steps.PRIME, part=part, progress="Priming")
  File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle/_runner.py", line 327, in _run_step
    getattr(part, step.name)()
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/__init__.py", line 737, in prime
    self._runner.prime()
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/_runner.py", line 116, in prime
    "override-prime", self._override_prime_scriptlet, self._primedir
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/_runner.py", line 162, in _run_scriptlet
    scriptlet_name, function_call.strip()
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/_runner.py", line 218, in _handle_builtin_function
    function(**function_args)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/__init__.py", line 749, in _do_prime
    dependency_paths = self._handle_elf(snap_files)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler/__init__.py", line 756, in _handle_elf
    elf_files = elf.get_elf_files(self.primedir, snap_files)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/elf.py", line 642, in get_elf_files
    elf_file = ElfFile(path=path)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/elf.py", line 215, in __init__
    elf_data = self._extract(path)
  File "/usr/lib/python3/dist-packages/snapcraft/internal/elf.py", line 230, in _extract
    elf = elftools.elf.elffile.ELFFile(fp)
  File "/usr/lib/python3/dist-packages/elftools/elf/elffile.py", line 50, in __init__
    self._identify_file()
  File "/usr/lib/python3/dist-packages/elftools/elf/elffile.py", line 209, in _identify_file
    raise ELFError('Invalid EI_CLASS %s' % repr(ei_class))
elftools.common.exceptions.ELFError: Invalid EI_CLASS b'\xff'

I don’t know which file it is looking at. The go tree does have some oddball files for test cases, it could be one of those.