$ repren --from '#include <a.h>' --to '#include <b.h>' .
error: found no parse patterns
Same with --literal:
$ repren --literal --from '#include <a.h>' --to '#include <b.h>' .
error: found no parse patterns
This is because it interprets the # as a comment character (in function parse_patterns()).
It would be nice if this comment logic did not apply when patterns are supplied directly via --from --to, and/or when --literal is given.