hola, buen día tengo problema para instalar la versión 1.26 ó 1.27, este es parte del error
ERROR: Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pip/internal/cli/base_command.py", line 164, in exc_logging_wrapper
    status = run_func(*args)
  File "/usr/local/lib/python3.6/site-packages/pip/internal/cli/req_command.py", line 205, in wrapper
    return func(self, options, args)
  File "/usr/local/lib/python3.6/site-packages/pip/internal/commands/install.py", line 339, in run
    reqs, check_supported_wheels=not options.target_dir
  File "/usr/local/lib/python3.6/site-packages/pip/internal/resolution/resolvelib/resolver.py", line 93, in resolve
    collected.requirements, max_rounds=try_to_avoid_resolution_too_deep
  File "/usr/local/lib/python3.6/site-packages/pip/vendor/resolvelib/resolvers.py", line 482, in resolve
    state = resolution.resolve(requirements, max_rounds=max_rounds)
  File "/usr/local/lib/python3.6/site-packages/pip/vendor/resolvelib/resolvers.py", line 349, in resolve
    self.add_to_criteria(self.state.criteria, r, parent=None)
  File "/usr/local/lib/python3.6/site-packages/pip/vendor/resolvelib/resolvers.py", line 173, in add_to_criteria
    if not criterion.candidates:
  File "/usr/local/lib/python3.6/site-packages/pip/vendor/resolvelib/structs.py", line 151, in bool
    return bool(self.sequence)
  File "/usr/local/lib/python3.6/site-packages/pip/internal/resolution/resolvelib/found_candidates.py", line 155, in bool
    return any(self)
  File "/usr/local/lib/python3.6/site-packages/pip/internal/resolution/resolvelib/found_candidates.py", line 143, in <genexpr>
    return (c for c in iterator if id(c) not in self.incompatible_ids)
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/resolution/resolvelib/found_candidates.py", line 47, in iter_built
    candidate = func()
  File "/usr/local/lib/python3.6/site-packages/pip/internal/resolution/resolvelib/factory.py", line 206, in make_candidate_from_link
    version=version,
  File "/usr/local/lib/python3.6/site-packages/pip/internal/resolution/resolvelib/candidates.py", line 287, in init
    version=version,
  File "/usr/local/lib/python3.6/site-packages/pip/internal/resolution/resolvelib/candidates.py", line 156, in init
    self.dist = self.prepare()
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 225, in prepare
    dist = self.prepare_distribution()
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 292, in prepare_distribution
    return preparer.prepare_linked_requirement(self.ireq, parallel_builds=True)
  File "/usr/local/lib/python3.6/site-packages/pip/internal/operations/prepare.py", line 482, in prepare_linked_requirement
    return self.prepare_linked_requirement(req, parallel_builds)
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/operations/prepare.py", line 528, in prepare_linked_requirement
    link, req.source_dir, self.download, self.download_dir, hashes
  File "/usr/local/lib/python3.6/site-packages/pip/internal/operations/prepare.py", line 223, in unpack_url
    unpack_file(file.path, location, file.content_type)
  File "/usr/local/lib/python3.6/site-packages/pip/internal/utils/unpacking.py", line 247, in unpack_file
    untar_file(filename, location)
  File "/usr/local/lib/python3.6/site-packages/pip/_internal/utils/unpacking.py", line 218, in untar_file
    with open(path, "wb") as destfp:
UnicodeEncodeError: 'ascii' codec can't encode character '\xe9' in position 112: ordinal not in range(128)
ln: failed to create symbolic link '/usr/bin/sngrep': File exists
al final se reinicia el servidor