IO::Compress versions from 2.207 before 2.220 for Perl ship a zipdetails CLI tool that crashes with undefined subroutine on Info-ZIP Unix Extra Field with 8-byte UID or GID. When decode_ux() in bin/zipdetails handles an Info-ZIP Unix Extra Field (tag 0x7875) with UID Size or GID Size set to 8, causing zipdetails to decode an 8-byte UID or GID value, it dispatches through decodeLitteEndian(), which calls a misnamed helper unpackValueQ. The actual function defined in the same file is unpackValue_Q (with underscore); the call raises 'Undefined subroutine &main::unpackValueQ' and the script exits with status 255. Library callers of IO::Compress and IO::Uncompress are not affected; the defect is in the bundled CLI tool.