On Wed, Jan 11, 2017 at 6:31 PM, Antonio Diaz Diaz <[email protected]> wrote: > Jim Meyering wrote: >> >> -export XZ_OPT = -8e >> +export XZ_OPT = --lzma2=preset=9e,dict=48MiB,pb=0 > > > Isn't this going to impact the use of pristine-tar? > https://packages.debian.org/sid/pristine-tar > > https://github.com/pah/pristine-tar/blob/master/pristine-xz states that: > -------------------------------------------------------------------- > The approach used to regenerate the original xz file is to figure out > how it was produced -- what compression level was used, etc. Currently > support is poor for xz files produced with unusual compression options. > --------------------------------------------------------------------
I would not let the existence of limitations in such a tool block the use of options to get better compression. But if it is an issue, then we can see it as an opportunity for improvement of pristine-tar. The dictionary size is already readily available via `xz -vv --list ...`, and if there is not yet a way to directly derive that `pb=0` setting, I'll bet its use can be derived without too much effort.
