Description of problem:
LLDB does not really work without its python2-lldb package but one cannot easily figure that out.

Version-Release number of selected component (if applicable):
FAIL: lldb-5.0.1-1.fc27.x86_64
FAIL: lldb-6.0.0-1.fc28.x86_64

How reproducible:
Always.

Steps to Reproduce:
dnf install lldb
lldb myprog
-> 6   	  std::vector<int> v (1, 2);
(lldb) n
(lldb) p v

Actual results:
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named lldb.embedded_interpreter
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'run_one_line' is not defined
(std::vector<int, std::allocator<int> >) $0 = size=1 {
  std::_Vector_base<int, std::allocator<int> > = {
    _M_impl = {
      _M_start = 0x0000000000614e70
      _M_finish = 0x0000000000614e74
      _M_end_of_storage = 0x0000000000614e74
    }
  }
}

Expected results:
(std::vector<int, std::allocator<int> >) $0 = size=1 {
  [0] = 2
}

Additional info:
It would be solved by:
  Recommends: python2-lldb
Or maybe even:
  Requires: python2-lldb
But then I do not know why is python2-lldb a separate package.
BTW do you know how to build LLDB for Python 3?  There is some six.py doing some Python 2<->3 compatibility.