Custom_component dependency issue in hassio

Hello all!

I am trying to create a new custom_component. It has 1 requirement:

REQUIREMENTS = ['tmpo==0.2.10']

When I install my custom component in hassio (running on a Rpi3) and restart HA, I get the following error when HA tries to install the dependency:

2018-07-26 11:29:28 ERROR (SyncWorker_14) [homeassistant.util.package] Unable to install package tmpo==0.2.10: Failed building wheel for pandas
Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2862, in _dep_map
    return self.__dep_map
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2669, in __getattr__
    raise AttributeError(attr)
AttributeError: _DistInfoDistribution__dep_map

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2853, in _parsed_pkg_info
    return self._pkg_info
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2669, in __getattr__
    raise AttributeError(attr)
AttributeError: _pkg_info

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/basecommand.py", line 228, in main
    status = self.run(options, args)
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/commands/install.py", line 318, in run
    self._warn_about_conflicts(to_install)
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/commands/install.py", line 442, in _warn_about_conflicts
    package_set, _dep_info = check_install_conflicts(to_install)
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/operations/check.py", line 89, in check_install_conflicts
    state = create_package_set_from_installed()
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/operations/check.py", line 39, in create_package_set_from_installed
    retval[name] = PackageDetails(dist.version, dist.requires())
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2613, in requires
    dm = self._dep_map
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2864, in _dep_map
    self.__dep_map = self._compute_dependencies()
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2873, in _compute_dependencies
    for req in self._parsed_pkg_info.get_all('Requires-Dist') or []:
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2855, in _parsed_pkg_info
    metadata = self.get_metadata(self.PKG_INFO)
  File "/usr/local/lib/python3.6/site-packages/pip/_vendor/pkg_resources/__init__.py", line 1405, in get_metadata
    return value.decode('utf-8') if six.PY3 else value
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf5 in position 5130: invalid start byte
2018-07-26 11:29:28 ERROR (MainThread) [homeassistant.requirements] Not initializing sensor.tmpo because could not install requirement tmpo==0.2.10
2018-07-26 11:29:28 ERROR (MainThread) [homeassistant.setup] Unable to prepare setup for platform sensor.tmpo: Could not install all requirements.

Does anyone know what is going wrong here? I have another custom component whose requirements are installed just fine.