Sometimes when a long list of files is printed, it must be streaming output to magit, which then get confused (by non-flushes) and leaves a bold ansi code, and then the magit-process buffer is hosed until manually killed. So two things should change for long file lists:
elide a long list of files (to not overwhelm tooling)
print a red delta, instead of yellow, to make elision obvious
Sometimes when a long list of files is printed, it must be streaming output to magit, which then get confused (by non-flushes) and leaves a bold ansi code, and then the magit-process buffer is hosed until manually killed. So two things should change for long file lists: