The later scripted diff only handles plain `assert x == y` lines.
Some remaining tests still use equality inside comprehensions, parenthesized asserts, and other shapes that the line-based rewrite would misread.
Rewrite those sites by hand first so the later mechanical conversion stays safe.
The commit also simplifies the dead `len(["errors"]) == 0` branch in `blocktools.py`, which can never be true.
dcd90fbe54