[RFC] New ports idea: github / gitorious / bitbucket direct support.

[perryh at pluto.rain.com]

Lev Serebryakov <lev at freebsd.org> wrote:

>  ... gzip, for example, has "timestamp" field in header.
>  Try this locally, without any [D]VCS:
>
> % mkdir test && echo "one" > test/one.txt && echo "two" > test/two.txt
> % tar czf test1.tar.gz test && sleep 5 && tar czf test2.tar.gz test
> % md5 test1.tar.gz test2.tar.gz
> MD5 (test1.tar.gz) = 7b7c763a9d1d4edca7b5b415ab297fec
> MD5 (test2.tar.gz) = 703ac5387b2bd1146434516f1d761ed9
> % gzip -d test1.tar.gz test2.tar.gz
> % md5 test1.tar test2.tar
> MD5 (test1.tar) = 0ba33aa8ff6bffeeeb2d96efc38eec85
> MD5 (test2.tar) = 0ba33aa8ff6bffeeeb2d96efc38eec85

That is arguably a bug in "tar czf" :)  but it is easy enough to
work around; we just need a checksum method -- e.g. SHA256_UNGZ --
that pipes the distfile through gunzip when computing its checksum.