In short, prepend your glob pattern with ./
.
I ran into this same problem and managed to find a related ffmpeg
bug report: https://trac.ffmpeg.org/ticket/5384. It looks like the filename parser considers the part before a colon to be a schema.
In that bug report, the answer said to use an explicit file:
prefix. That worked for me too, but only if I had a single file as input. For more than one file, I was able to use the workaround the bug author used (prepend the current directory).
More generally, it would seem that any path separator (i.e. slash char) tricks the filename parser into doing the right thing. For example, it should also work if you provide an absolute path for the input filenames.