makerel: always use ustar format

[haarg]

When generating release tarballs, always use ustar format. The ustar format is one of the POSIX standard formats, and is the basis for future tar formats. It supports all of the features we need to create a release tarball. The newer formats support extended attributes that can produce warnings when extracting on some systems. This includes attributes like LIBARCHIVE.xattr.com.apple.quarantine, set on macOS systems on files downloaded from the internet. Using the ustar format prevents those attributes from being stored in the tarball and avoids the warnings.

[haarg]

Fixes #22245

[jkeenan]

When generating release tarballs, always use ustar format. The ustar format is one of the POSIX standard formats, and is the basis for future tar formats. It supports all of the features we need to create a release tarball. The newer formats support extended attributes that can produce warnings when extracting on some systems. This includes attributes like LIBARCHIVE.xattr.com.apple.quarantine, set on macOS systems on files downloaded from the internet. Using the ustar format prevents those attributes from being stored in the tarball and avoids the warnings.

When generating release tarballs, always use ustar format. The ustar format is one of the POSIX standard formats, and is the basis for future tar formats. It supports all of the features we need to create a release tarball. The newer formats support extended attributes that can produce warnings when extracting on some systems. This includes attributes like LIBARCHIVE.xattr.com.apple.quarantine, set on macOS systems on files downloaded from the internet. Using the ustar format prevents those attributes from being stored in the tarball and avoids the warnings.

I don't know enough about the different tar formats to say whether or not we should be using ustar. I did, however, configure and build perl, then call perl Porting/makerel -r [rootdir] -x -c for both blead and this p.r. I then compared the resulting tarballs and the only difference I found was (as expected) in Porting/makerel. So LGTM.

[Grinnz]

Oh, I see now the CPAN module is canonical for EU:MM.

See Perl-Toolchain-Gang/ExtUtils-MakeMaker#349 for discussion there.

[tonycoz]

Going by the discussion in Perl-Toolchain-Gang/ExtUtils-MakeMaker#349 wouldn't we be better off using ptar?

Since:

• not all tars accept --format=ustar
• some tars accept --format=ustar but create an empty archive, or not include some files in the archive ( Always use the ustar format of tar xsawyerx/module-starter#73 (comment) )

while ptar always produces ustar

[haarg]

All of the tar implementations we care about support --format=ustar.

Producing an empty tarball requires a rather specific system setup that is not common. It's something I ran into before, but is no longer relevant to me. It's also more of an issue for CPAN releases, because they are often uploaded without being tested directly.

makerel doesn't need to work on as diverse of a set of systems as ExtUtils::MakeMaker, and we always verify the tarball that is produced.