[QUESTION] how to get subsetting string (whitelist)?

[the-hotmann]

I know that this command normally should work and just return me the "subsetting string" (here called "whitelist") which is exclusively used by Roboto:

glyphhanger ./public/index.html --string --spider-limit=0 --family=' Roboto' .

something like 0123456789ÄÖÜABCDEFGHIJKLMNOPQRSTUVWXYZäöüabcdefghijklmnopqrstuvwxyz-,.&§ß?!©

But apparently its's not working and exists with the following code:

GlyphHanger Fetch Error: Error: Failed to launch the browser process!

I have not installed any other dependencies as I want this sololy NPM/YARN based and no other extensions like Python based, since I use this in a setup that should be as clean/minimalistic as possible.

Is there a way with glyphhanger (without installing any non NPM dependencies) to get to output the subsetting char-string for ALL html files in a folder (also if they are not linked within each other!) which are JUST used in the end by the specified font?

Weird question maybe, but if you dont understand what I mean please ask, and I will explain again.

My goal is it to create the perfect subsetting char-string for both fonts which I use and to the subset them both with eachs perfect subsetting string. But I would like to stay within NPM

Also I miss the option to search for like:

glyphhanger ./public/**.html --string --family=' Roboto'
which should match ALL "*.html" files in the folder "public" and all subfolders. Since I want to match them all and not having to list them.

Thanks in advance!