What to do with xz?

[Zbigniew Luszpinski]

Hello,

Terry Chan wrote in commit 7ca5e78a4e8347e4b6b995b76a63966e22c53d94:
"gzip: KEEP the source as tar.gz NOT tar.xz
This is really stupid to require the xz module to be able to unpack the GZIP
source code. Everyone has gzip on their box from the Lunar ISO. Do NOT change
this module over to tar.xz. This means you!"

I would like to know if we are for or against xz tarballs in moonbase. What are rules of using xz in moonbase.
There are 5 choices:
a) Boycott xz and keep using gzip,bzip and compress for everything. There is no problem for me to convert modules from xz to gz before commit. Script keeping this done is trivial to write and use for me.
b) Prepare a list of blacklisted modules which should always be legacy compressed (this is important because gnu.org only uses gz and xz)
c) make DETAILS conditional so those who have xz can use smaller and faster downloads. Other will use legacy gz and older.
d) ugly hack: add xz to DEPENDS of every xz/lzma source packed module
e) Return to my plan of comfortable migration which was:
1) lunar depends xz + patched generic unpack plugin (working patch already present on ML)
2) lunar update will force patched and updated lunar module to be installed as first and xz dependency will be also installed so nobody is hurt even if he/she has fresh install from ISO.
3) Now we can start pushing xz packed tarballs to moonbase because everyone who do lunar update will have support for xz.
Because 1st point was not successful done to the end all plan collapsed. But we can always try it again if there is more acceptance.

I prefer e) solution.
Because xz is used by new gnu.org releases I vote for putting xz on new ISO because soon the most new core modules can be in xz or gz tarball. xz depacks almost equally fast as gzip and tarballs are ~40% smaller.

For me it is smart to keep gzip packed with other compressor because if I loose gzip I can still unpack it, build it and install it without the need of having gzip. Believe or not but some people do not have iso after installation. For example they burn it on CD-RW, install and erase disc. Or they are lazy to not search for it. For me this was obvious: bzip2 is packed with gzip, xz is packed with bzip2 so gzip should be packed with xz to close the security circle. Gnu organisation only supports gzip and xz for new releases on their servers - that is why bzip2 was not chosen by me.

Because I had to rewrite xz to external unpack plugin I realized that someone who has not yet xz will receive on screen message that xz is needed to unpack archive. Maybe this is not elegant as e) solution but works. The xz message is only displayed once if someone will install xz module after this message. Not a big issue.

have a nice day,
Zbigniew Luszpinski