Re: [PULL v2 00/22] Build system + misc changes for 2020-10-16

[Peter Maydell <peter.maydell@linaro.org>]

On Sat, 17 Oct 2020 at 17:37, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Ok, so the warning remains when everything is fixed, though the text is
> slightly different (and better):
>
>   Library iconv found: NO
>   Run-time dependency ncursesw found: NO (tried pkgconfig)
>   Library ncursesw found: YES
>   Library cursesw found: NO
>   ../src/meson.build:540: WARNING: curses library not usable, disabling
>
> In this case, meson.build warns because curses doesn't always have a .pc
> file; therefore when meson.build doesn't find the headers it can't but
> proceed without curses suport.

> The "library found"/"curses support disabled" situation is a bit
> confusing, which is why I've been adding some kind of message for those
> few cases in which we cannot just use pkg-config.  (The multipath test
> is already warning, but those libraries are a bit niche so you probably
> don't even have the libraries installed).
>
> Peter, I would like your input on these two things:
>
> 1) are you going to pull v3 and I can fix up everything later?  Or would
> you prefer me to send v4 once the new curses test is reviewed?

If the only issue with v3 is that stray warning message I'm
OK with applying it and improving the test later.

> 2) would you prefer the "library was found but headers weren't" to warn,
> issue an informative message, or be completely silent?

I think the build system should just say whether it found a
working curses setup or not, and do our usual "this is fatal
if --enable-whatever, otherwise just disable feature". If we
happen to have convenient information to put in whatever
the new build system's equivalent of config.log is [ie the
saved-for-debug-purposes log], we might as well put it in,
but we don't need to put that in the stdout. (We shouldn't
say "ncurses found: YES" unless we actually found a working
version, ideally.)

thanks
-- PMM