use host compressor for rootfs

Quoted 5 lines · Philippe Reynes

I've missed this "mandatory dependancy".
I suppose that this dependancy is usefull to uncompress tarball. But I think that the compilation of firmware should be done with tools compiled by buildroot.

Quoted 7 lines

If lzma is used to compress the rootfs, then lzma is compile by builtoot. If gzip is used to compress the rootfs, then we use local gzip. It's not very "coherent".
And using compiled binary with buildroot increase chance to regenerate firmware on (very) different machine.

And I agree with you, it's not a "real" issue, it's more a "nice to have".

Well, I guess there are two important things here:

1) Buildroot tries to avoid building native utilities needlessly. So when possible, we try to use the tools available on the machine, in order to keep the overall build time as reasonable as possible.

2) gzip and bzip2 are widely available tools, which haven't caused any compatibility issue in years. On the other hands, tools like lzma, xz and so on are a lot less widely available. They may not even be available at all on old Linux distributions that some companies are still using.

Both of these points combined explain why we handle gzip/bzip2 differently than lzma/xz.