[Buildroot] [PATCH v2 2/2] Makefile: pass host PKG_CONFIG_PATH at "make menuconfig" time

[Yann E. MORIN <yann.morin.1998@free.fr>]

Bj?rn, All,

On 2015-01-02 22:34 +0100, Bj?rn Forsman spake thusly:
> On 2 January 2015 at 22:28, Bj?rn Forsman <bjorn.forsman@gmail.com> wrote:
> > On 2 January 2015 at 17:16, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> >> Bj?rn, All,
> >>
> >> On 2015-01-01 21:54 +0100, Bj?rn Forsman spake thusly:
> >>> Buildroot unexports PKG_CONFIG_PATH in the top-level Makefile for purity
> >>> reasons. But it has an unfortunate side-effect in that "make menuconfig"
> >>> will not (necessarily) be able to pick up ncurses via host pkg-config,
> >>> breaking "make menuconfig" on systems where ncurses is installed in a
> >>> non-standard location.
> >>>
> >>> This patch saves the original PKG_CONFIG_PATH variable in
> >>> HOST_PKG_CONFIG_PATH and restores the original PKG_CONFIG_PATH variable
> >>> only in the sub-processes that builds the various menuconfig/nconfig/...
> >>> targets.
> >>>
> >>> With this change, I am able to run "make menuconfig" on NixOS[1].
> >>>
> >>> [1]: http://nixos.org/
> >>>
> >>> Signed-off-by: Bj?rn Forsman <bjorn.forsman@gmail.com>
> >>> ---
> >>>  Makefile | 6 +++++-
> >>>  1 file changed, 5 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/Makefile b/Makefile
> >>> index 5e0b4f2..2f1108f 100644
> >>> --- a/Makefile
> >>> +++ b/Makefile
> >>> @@ -264,6 +264,7 @@ export HOSTAR HOSTAS HOSTCC HOSTCXX HOSTFC HOSTLD
> >>>  export HOSTCC_NOCCACHE HOSTCXX_NOCCACHE
> >>>
> >>>  # Make sure pkg-config doesn't look outside the buildroot tree
> >>> +export HOST_PKG_CONFIG_PATH=$(PKG_CONFIG_PATH)
> >>
> >> I think you'd want to do an immediate assignment here, and not do an
> >> export (see below):
> >>
> >>     HOST_PKG_CONFIG_PATH:=$(PKG_CONFIG_PATH)
> >
> > Will fix.
> 
> Some comments. There are other HOST_* variables that are exported from
> the top-level Makefile. I guess that's why I used 'export' in the
> first place.

You're right. I believe export is not needed, but for consistency sake,
I understand you would want to use export on it.

Do with an export if you want, I won't complain much. ;-) But state in
the commit log that it is not strictly required for the current use-case,
and is here just for consistency with other similarly-named variables.

> For now, nobody but Buildroot itself uses
> HOST_PKG_CONFIG_PATH (well, when this patch gets in), but I can see a
> future where pkg-config is used within Buildroot for other host
> packages too. But it is of course trivial to add the "export" at any
> time :-)

Hey! :-)

Thanks!

Regards,
Yann E. MORIN.

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