Re: [PATCH] perf tools: Speed up the perf build time by simplifying the perf --version string generation

[Ingo Molnar <mingo@kernel.org>]

* Arnaldo Carvalho de Melo <acme@infradead.org> wrote:

> Em Tue, Oct 30, 2012 at 10:48:52AM +0100, Ingo Molnar escreveu:
> > 
> > * Ingo Molnar <mingo@kernel.org> wrote:
> > 
> > > Does -l work?
> > > 
> > > Alternatively, please replace:
> > > 
> > >   git tag --list "v[0-9].[0-9]*" | tail -1
> > > 
> > > with:
> > > 
> > >   git tag | tail -1 | grep -E "v[0-9].[0-9]*"
> > > 
> > > which is just as fast.
> > 
> > make that:
> > 
> >     git tag 2>/dev/null | tail -1 | grep -E "v[0-9].[0-9]*"
> > 
> > this will work silently even if Git is not installed.
> 
> But we first check if we have a .git, that doesn't guarantees 
> that git is installed, but makes it a lot likely, no? 
> [...]

Not necessarily - say a home directory is NFS shared to multiple 
test boxes, one does not have Git installed.

> Redirecting stderr to null would need to be done in more 
> places, so we would need to use something like what we do for 
> xmlto/asciidoc, $(call get-executable,$(GIT))

It at least solves it in this particular case, and I tested it 
with Git uninstalled, there's no extra message just a proper 
error code the script can use to fall back to the toplevel 
Makefile for version info.

Thanks,

	Ingo