Loading textures from .jar file not found

When loading textures from a packed jar file it fails to find the textures. but when the jar is extracted and the folder used, no issues.

Works:

renders["Test"] = {
    "world"  : "Test",
    "title": "Test Overworld Daytime",
    "rendermode": smooth_lighting,
    "dimension": "overworld",
    'texturepath' : "C:/Users/***/AppData/Roaming/.minecraft/versions/1.15.2/1.15.2"
}

Doesnt work

renders["Test"] = {
    "world"  : "Test",
    "title": "Test Overworld Daytime",
    "rendermode": smooth_lighting,
    "dimension": "overworld",
    'texturepath' : "C:/Users/***/AppData/Roaming/.minecraft/versions/1.15.2/1.15.2.jar"
}

Does not appear to be an issue in the upstream master branch (e5ec41fcf931a9024cc39ee6536e8d6095f9fff9)

C:\Users\***\AppData\Local\Programs\Python\Python37-32\python.exe C:/Datafile/***/Documents/Minecraft-Overviewer/overviewer.py --config=C:\Datafile\***\Documents\Minecraft-Overviewer\test_Conf\conf.py --force-render --processes=4
2020-03-25 14:20:31  Welcome to Minecraft Overviewer!
2020-03-25 14:20:31  Generating textures...
2020-03-25 14:20:31 E Could not find the textures while searching for 'assets/minecraft/blockstates\cyan_stained_glass.json'. Try specifying the 'texturepath' option in your config file.
Set it to the path to a Minecraft Resource pack.
Alternately, install the Minecraft client (which includes textures)
Also see <http://docs.overviewer.org/en/latest/running/#installing-the-textures>
(Remember, this version of Overviewer requires a 1.15-compatible resource pack)
(Also note that I won't automatically use snapshots; you'll have to use the texturepath option to use a snapshot jar)

Process finished with exit code 1

DragonDev1906 / Minecraft-Overviewer

Loading textures from .jar file not found #2