On armh, what is compressed by compress cannot be uncompressed by uncompress. builder@armh:~/RPM/BUILD/file-5.43$ compress COPYING builder@armh:~/RPM/BUILD/file-5.43$ uncompress COPYING.Z insize:93 posbits:55 inbuf:00 06 10 AA 00 (7) uncompress: corrupt input Verify with gzip: builder@armh:~/RPM/BUILD/file-5.43$ gzip -d COPYING.Z gzip: COPYING.Z: corrupt input. Use zcat to recover some data.