Re: [PATCH] kbuild: Fail the build early when no lz4 present

From: Masahiro Yamada
Date: Tue Oct 16 2018 - 05:18:34 EST

On Fri, Oct 12, 2018 at 12:33 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
> On Fri, Oct 12, 2018 at 12:08:07AM +0900, Masahiro Yamada wrote:
> > Install lz4c, and run 'make' again.
> > Almost all objects have been built there,
> > so you will finish it soon.
> So when this LZ4 thing got added at the time, the lz4 package had to be
> downloaded and built and installed and it wasn't as easy as zypper in
> lz4 or apt-get install lz4.
> And I *might* install it if there were a human readable error message
> which would tell me so.
> And we should strive to be as user-friendly as possible. And no, this:
> /bin/sh: 1: lz4c: not found
> make[2]: *** [arch/x86/boot/compressed/Makefile:145: arch/x86/boot/compressed/vmlinux.bin.lz4] Error 1
> make[2]: *** Waiting for unfinished jobs....
> make[1]: *** [arch/x86/boot/Makefile:112: arch/x86/boot/compressed/vmlinux] Error 2
> make: *** [arch/x86/Makefile:290: bzImage] Error 2
> make: *** Waiting for unfinished jobs....
> is not user-friendly.
> > If you are building up a compile-test machine,
> > you will probably need to install various tools anyway.
> Yes, and look how perf tool solves this. Much much better.
> > I do not want to add ugly checks in random places.
> That's fair.
> What would be a fitting place to add such checks and be able to issue a
> human-readable error message to people?

Sorry for delay.

I have been thinking of this
because I have a motivation to
move libelf check in the top Makefile to somewhere else.

I just made a trial.

Best Regards
Masahiro Yamada