[Bug]: Zarr 2.18.0 with Blosc about hdmf-zarr

[oruebel]

From the traceback it looks like this fails when it tries to read the first element of the data set data = zarr_obj[0] and it looks like the error occurs in numcodec rather than Zarr. What confuses me is the error ValueError: buffer source array is read-only, which seems to indicate that blosc wants write access even when reading from file. I'm wondering whether this may be an issue in Zarr or numcodec instead of hdmf_zarr

A couple of things to try:

• Change the mode during reading to a instead of r to see if that fixes the issue, i.e., change this line to with BACKEND_NWB_IO[backend](path=nwbfile_path, mode="a") as io:. If that works, then I think this may be an issue in Zarr.
• Can you also try reading the file with just Zarr, i.e,. open the file and try to read data = zarr_obj[0] from the dataset that causes the issue? If that works, another thing to try is to open with consolidated metadata (because hdmf_zarr uses consolidated metadata by default)

[oruebel]

@mavaylon1 can you take this from here.

[mavaylon1]

@oruebel I can, but I probably won't take a look till earliest end of next week. Does that fit your timeline?

[mavaylon1]

Possibly related: #195

[mavaylon1]

This seems to have been resolved by my fix and release in #195