gsub() in regex mode treats backslashes in the REPLACEMENT string as
escape sequences and silently drops them. A Windows corpus path is full of
them, so C:\Users\RUNNER\AppData\... was substituted into the view SQL
as C:UsersRUNNERAppData... and every DuckDB read failed with 'No files
found that match the pattern'.
Effect: uscogdata could not read a LOCAL corpus on Windows at all -- the
bundled fixture included, so the entire test suite failed there, and any
cog_mirror() copy was unusable. Remote https URLs were unaffected, having
no backslashes, which is part of why it stayed hidden.
The bug predates the {long_files} token; it lived in the original {url}
substitution since that code was written. Nothing ever ran on Windows
until the GitHub mirror's check matrix existed, which found it on its
first run: 14 of 15 Windows failures were this, the 15th a downstream
consequence of view registration failing.
fixed = TRUE treats pattern and replacement as literal text. The
regression test reproduces on any platform -- it is string handling, not
filesystem behaviour, so it needs no Windows runner.