`copy_tree()` excluded `*.png` from the scratch tree, which was right when the
only PNGs anywhere were libpng's and SDL_image's test corpora -- 39 MB that
nothing in this build reads. `docs/images/` changed that: `docs_examples`
asserts that every `screenshot=` block has its figure, so a copy with no images
fails thirteen blocks, the *baseline* comes back red, and the run aborts with
"Fix the suite before mutation testing" before mutating anything.
Mutation testing has therefore been unrunnable since the figures landed, and it
fails in the one way this repository's own notes warn about: looking like the
thing it measures is broken.
Keep the project's PNGs, still drop the dependencies'. The pattern list cannot
express that -- `ignore_patterns` matches basenames -- so it becomes a function
that adds the `*.png` rule only under `deps/`.
Verified: `--target src/symtab.c --max-mutants 2` now reports "Baseline OK." and
scores both mutants, where every invocation before this aborted.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Andrew Kesterson
caebc1a174
