• Go to https://dumps.wikimedia.org/other/pageview_complete/monthly/ and fetch one of the dumps
• Try to read it with command like bzip2 -d pageviews-202106-user.bz2

What happens?:

File cannot be uncompressed.

$ bzip2 -dc pageviews-202106-user.bz2 
bzip2: pageviews-202106-user.bz2 is not a bzip2 file.

What should have happened instead?:

Either publish these dumps as bzip2 archives (daily archives *are* correctly published). Or document their type and format and possible change the extension. In this particular case it would be probably
pageviews-202106-user.parquet because these files are Parquet files with schema:

{
  "type" : "record",
  "name" : "hive_schema",
  "fields" : [ {
    "name" : "line",
    "type" : [ "null", "string" ],
    "default" : null
  } ]
}

Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc: