Package does not declare all dependencies

[eyck]

When installing wal using pip on a CentOS7 OS and runnign wawk I get:

Traceback (most recent call last):
File "/home/xxx/git/TGC-UVM/riscv-dv-venv/bin/wawk", line 5, in <module>
from wawk.wawk import run
File "/home/xxx/git/TGC-UVM/riscv-dv-venv/lib64/python3.6/site-packages/wawk/[wawk.py](http://wawk.py/)", line 6, in <module>
from wal.core import Wal
File "/home/xxx/git/TGC-UVM/riscv-dv-venv/lib64/python3.6/site-packages/wal/[core.py](http://core.py/)", line 7, in <module>
from wal.eval import SEval
File "/home/xxx/git/TGC-UVM/riscv-dv-venv/lib64/python3.6/site-packages/wal/[eval.py](http://eval.py/)", line 2, in <module>
from wal.ast_defs import Operator, Symbol, ExpandGroup
File "/home/xxx/git/TGC-UVM/riscv-dv-venv/lib64/python3.6/site-packages/wal/ast_[defs.py](http://defs.py/)", line 2, in <module>
from dataclasses import dataclass
ModuleNotFoundError: No module named 'dataclasses'

After running pip3 install dataclasses everything works fine.