On Mon, Nov 09, 2020 at 05:14:24PM +0100, Thomas Monjalon wrote:
> 09/11/2020 16:44, Bruce Richardson:
> > On Mon, Nov 09, 2020 at 04:28:16PM +0100, Thomas Monjalon wrote:
> > > 09/11/2020 15:55, Ferruh Yigit:
> > > > If the 'PKG_CONFIG_PATH' is set in the environment before script run,
> > > > 32 bit still uses that value for 64-bits libraries.
> > > >
> > > > From the build log:
> > > >
> > > > "
> > > > Using DPDK_TARGET i386-pc-linux-gnu
> > > > meson -Dexamples=l3fwd --buildtype=debugoptimized --werror
> > > > -Dc_args=-m32 -Dc_link_args=-m32
> > > > /tmp/dpdk_maintain/self/dpdk/devtools/.. ./build-32b
> > > > ...
> > > > Using 'PKG_CONFIG_PATH' from environment with value:
> > > > '/usr/local/lib64/pkgconfig/
> > > > "
> > > >
> > > > This causes build error when linking with the found libraries.
> > > >
> > > > Reproduced with 'librte_bpf' which only has 64 bit installed but still
> > > > enables building 'af_xdp' and link fails.
> > > >
> > > > To fix this, using default 'PKG_CONFIG_PATH' variable unless
> > > > 'CUSTOM_PKG_CONFIG_PATH' set, and set the 'CUSTOM_PKG_CONFIG_PATH' for
> > > > 32 bit build.
> > > >
> > > > Fixes: 9b83106d8784 ("devtools: test 32-bit build")
> > > >
> > > > Signed-off-by: Ferruh Yigit <ferruh.yi...@intel.com>
> > > > ---
> > > > Cc: Bruce Richardson <bruce.richard...@intel.com>
> > > > Cc: Thomas Monjalon <tho...@monjalon.net>
> > > >
> > > > v2:
> > > > * Enable overwriting default 'PKG_CONFIG_PATH' value
> > >
> > > It was not my conclusion.
> > > I think we can just reset all env vars.
> > >
> >
> > Perhaps, but I think that may cause more problems for people who want
> > custom CFLAGS and LDFLAGS for building with extra 3rd-party packages.
> > While this can be done using the config script that is sourced in, I
> > suspect most of us do not use such a script.
> >
> > Therefore I'd suggest rather than clearing the env vars globally, we just
> > override them temporarily for the 32-bit, using CFLAGS32, LDFLAGS32,
> > PKG_CONFIG_PATH32 instead. That allows someone to have a 32-bit and 64-bit
> > version of e.g. libbpf installed, with a PKG_CONFIG_PATH pointing to each.
>
> So you want to duplicate all vars just to avoid writing them cleanly in a
> file?
> And what happens for other targets?
>
> I'm tending to nack this approach.
> There is no problem in using a clean config file.
>
Well, when you put it that way :-)
However, I was only thinking of the 3 variables above, though really it's
only the PKG_CONFIG_PATH that is going to be the most likely culprit, so
supporting just one extra var "PKG_CONFIG_PATH_32" seems reasonable.
I'm also ok with your solution of just clearing the environment and relying
on a config file too, though.
/Bruce
