Re: [PATCH] qemu: access host pkg-config via HOSTTOOLS

["Richard Purdie" <richard.purdie@linuxfoundation.org>]

On Fri, 2020-07-10 at 10:48 -0700, Taras Kondratiuk wrote:
> On some build hosts qemu-system-native fails to build with errors:
> like:
> > build/tmp/work/x86_64-linux/qemu-system-native/4.1.0-r0/qemu-4.1.0/qemu-keymap.c:16:10: fatal error: xkbcommon/xkbcommon.h: No such file or directory
> >    16 | #include <xkbcommon/xkbcommon.h>
> >       |          ^~~~~~~~~~~~~~~~~~~~~~~
> > compilation terminated.
> > make: *** [build/tmp/work/x86_64-linux/qemu-system-native/4.1.0-r0/qemu-4.1.0/rules.mak:69: qemu-keymap.o] Error 1
> 
> This is a combination of two factors:
> 1. In our setup we use native toolchain from buildtools-tarball because
>    default host GCC on some machines is too old.
> 2. Qemu recipe adds host pkg-config paths to PKG_CONFIG_PATH using
>    hardcoded pkg-config tool's location (/usr/bin:/bin).  Added by
>    commit 68a5ed337f8f ("qemu: fix qemu-native pkg-config paths")
> 
> Host xkbcommon package is detected in configure. But then the toolchain
> can't find headers because it uses headers from buildtools-tarball only.
> 
> Instead of using hardcoded location, use pkg-config via HOSTTOOLS. It
> will pick up correct pkg-config from PATH and avoid configuration
> discrepancies.
> 
> Signed-off-by: Taras Kondratiuk <takondra@cisco.com>
> ---
>  meta/conf/bitbake.conf              | 2 +-
>  meta/recipes-devtools/qemu/qemu.inc | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
> index 353caacef986..fae1147d397c 100644
> --- a/meta/conf/bitbake.conf
> +++ b/meta/conf/bitbake.conf
> @@ -488,7 +488,7 @@ HOSTTOOLS += " \
>      cpp cut date dd diff diffstat dirname du echo egrep env expand expr false \
>      fgrep file find flock g++ gawk gcc getconf getopt git grep gunzip gzip \
>      head hostname iconv id install ld ldd ln ls make md5sum mkdir mknod \
> -    mktemp mv nm objcopy objdump od patch perl pr printf pwd \
> +    mktemp mv nm objcopy objdump od patch perl pkg-config pr printf pwd \
>      python3 ranlib readelf readlink realpath rm rmdir rpcgen sed seq sh \
>      sha1sum sha224sum sha256sum sha384sum sha512sum \
>      sleep sort split stat strings strip tail tar tee test touch tr true uname \
> diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
> index d41cc8f200b3..881a5ba65025 100644
> --- a/meta/recipes-devtools/qemu/qemu.inc
> +++ b/meta/recipes-devtools/qemu/qemu.inc
> @@ -94,7 +94,7 @@ EXTRA_OECONF_append = " --python=${HOSTTOOLS_DIR}/python3"
>  
>  do_configure_prepend_class-native() {
>  	# Append build host pkg-config paths for native target since the host may provide sdl
> -	BHOST_PKGCONFIG_PATH=$(PATH=/usr/bin:/bin pkg-config --variable pc_path pkg-config || echo "")
> +	BHOST_PKGCONFIG_PATH=$(${HOSTTOOLS_DIR}/pkg-config --variable pc_path pkg-config || echo "")
>  	if [ ! -z "$BHOST_PKGCONFIG_PATH" ]; then
>  		export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$BHOST_PKGCONFIG_PATH
>  	fi

qemu is a little special, its about the only thing we let look into the
system for things like this. We really don't want pkg-config available
generally in HOSTTOOLS.

I'm not 100% sure I understand how this is fixing things either. Is
this using the pkg-config from your buildtools tarball instead?

Cheers,

Richard