Not exactly a bug, but I didn't know where else to report this:
It appears DEB files were left out of the 7-Zip v9.32 alpha Readme.txt list of Supported formats for Unpacking only (having appeared in the same list in several previous versions, since at least v9.22, and probably back to v2.30 when DEB archives were first supported).
The same v9.32 alpha Readme.txt list also has added AR files at the beginning of the list just before ARJ files.
I assume both of these changes are unintentional. However, per Wikipedia, DEB files use a standard UNIX AR format; so perhaps the change is intentional (???) ...If so, perhaps a comment to that effect needs to be included in the Readme.txt file.