flit: 3.5.1: cannot add module metadata in project tree

I’m trying ot add .{dist|egg}.info metadata in structlog module which is using as build backend flit and looks like it is not possible to do that

+ cd structlog-21.5.0
+ /usr/bin/python3 -sBm build -w
* Creating venv isolated environment...
* Installing packages in isolated environment... (flit_core >=3.4,<4)
* Getting dependencies for wheel...
* Building wheel...
Successfully built structlog-21.5.0-py3-none-any.whl
+ pip install -e .
Defaulting to user installation because normal site-packages is not writeable
Obtaining file:///home/tkloczko/rpmbuild/BUILD/structlog-21.5.0
  Installing build dependencies ... done
  Checking if build backend supports build_editable ... done
  Getting requirements to build editable ... done
  Preparing editable metadata (pyproject.toml) ... done
Building wheels for collected packages: structlog
  Building editable for structlog (pyproject.toml) ... done
  Created wheel for structlog: filename=structlog-21.5.0-py3-none-any.whl size=8107 sha256=e193ec3c74a678106d51a2b593a7d5037c7fa94cc2fdeae0fbb66b7eb0081bc1
  Stored in directory: /tmp/pip-ephem-wheel-cache-68zzmr4f/wheels/35/89/3a/cd47c49b9d6c16185c5a0f83a41dd101771681f0d2bcadf8f3
Successfully built structlog
Installing collected packages: structlog
  Attempting uninstall: structlog
    Found existing installation: structlog 21.5.0
    Uninstalling structlog-21.5.0:
      Successfully uninstalled structlog-21.5.0
Successfully installed structlog-21.5.0

Loks like pip is not able to take [project] section from pyproject.toml. How can I do that? flit command seems does not offer anything like generate .{dist|egg}.info directory 😕