Failure to extract from `deflate` .Z file

[raymondben]

These two .Z files (sea ice concentration data, renamed with .txt extension to allow upload here) should decompress to about 840k each. 20231030.nc.Z silently seems to not decompress at all:

> ff <- archive::file_read("20231030.nc.Z", mode = "rb")
> foo <- readBin(ff, what = "raw", n = 1e7)
> length(foo)
[1] 98598
> file.size("20231030.nc.Z")
[1] 98598

whereas 20231026.nc.Z decompresses fine. They are both from the same provider but I notice that the compression method may have changed:

$ uncompress -vl 20231030.nc.Z
method  crc     date  time           compressed        uncompressed  ratio uncompressed_name
defla ffffffffffffffff May  9 09:09               98598                  -1   0.0% 20231030.nc

$ uncompress -vl 20231026.nc.Z
method  crc     date  time           compressed        uncompressed  ratio uncompressed_name
compr ffffffffffffffff May  9 09:09               95167                  -1   0.0% 20231026.nc

(i.e. the provider has switched from compress to deflate?)

Is there any way to read the deflate file? I tried specifying file_read(..., filter = "something") without success.

• thanks.

20231030.nc.Z.txt
20231026.nc.Z.txt