Running ALE on HRSC

I see ALE running on PDS IMG and ISIS cubes in example, but I get the same not supported error. Confused. I refreshed ALE install just in case but no luck.

ISIS 8bit cubes here and PDS3 IMGs located here:
/scratch/thare/SOCET_GXP/test_models_GXP/HRSC/Gale_Crater_orbit_h4235/stereo_images

here is how I am running ALE
```
import ale
import json
import os

import glob
for infile in glob.glob("*8b*.cub"):
print(infile)
usgscsm_str = ale.loads(infile)
csm_isd = os.path.splitext(infile)[0] + '.json'
with open(csm_isd, 'w') as isd_file:
isd_file.write(usgscsm_str)

```