[Buildroot] [PATCH v2 1/1] package/dhcp: add host-gawk to dependencies and build environment

[Arnout Vandecappelle]

On 14/02/2021 15:54, Sergey Matyukevich wrote:
> DHCP package may silently fail to install binaries to the target image.
> The problem occurs when buildroot configuration and build host provide
> different flavors of awk. For instance, mawk on build host and gawk in
> buildroot output/host. In this case isc-dhcp configure script detects
> gawk in output/host and generates Makefiles specifying gawk without
> absolute path. During Buildroot installation phase, those Makefiles
> are used to install dhcp binaries. They attempt to use gawk without
> absolute path. However build host does not have gawk.
> 
> To resolve the issue add host-gawk to the list of dhcp dependencies
> and explicitely specify absolute path to host-gawk.
> 
> Signed-off-by: Sergey Matyukevich <geomatsi at gmail.com>

 Heiko recently posted a patch that does the same thing, and I applied that one
because it only adds the dependency when the server is enabled (client doesn't
need gawk).

 Thanks!

 Regards,
 Arnout

> ---
> 
> Changes v1 -> v2 (after review and tests by Thomas Petazzoni):
>  - suggested change is the same
>  - root cause is figured out and commit message updated
> 
> The root cause is explained in commit message. Here are the steps
> to reproduce the issue.
> 
> Buildroot Docker image at support/docker/Dockerfile provides a way to
> reproduce the issue. This docker image includes mawk. Each of the
> following cases starts from default qemu_x86_defconfig:
> 
> 1. Keep using uclibc, enable isc-dhcp server and client
> Buildroot does not have any awk flavor installed in output/host, so
> mawk from build host is used. Build dhcp. The result is ok: both
> dhclient and dhcpd are installed on the target.
> 
> 2. Switch to glibc, enable isc-dhcp server and client
> Note that glibc package has host-gawk among its dependencies. So in
> this case build host awk (mawk) differs from buildroot host awk (gawk).
> Build dhcp. The result is not ok: neither dhclient nor dhcpd are
> installed to the target.
> 
> Regards,
> Sergey
> 
>  package/dhcp/dhcp.mk | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/package/dhcp/dhcp.mk b/package/dhcp/dhcp.mk
> index 988c7792dc..4a9e98485c 100644
> --- a/package/dhcp/dhcp.mk
> +++ b/package/dhcp/dhcp.mk
> @@ -10,6 +10,7 @@ DHCP_INSTALL_STAGING = YES
>  DHCP_LICENSE = MPL-2.0
>  DHCP_LICENSE_FILES = LICENSE
>  DHCP_DEPENDENCIES = bind
> +DHCP_DEPENDENCIES = bind host-gawk
>  DHCP_CPE_ID_VENDOR = isc
>  
>  # use libtool-enabled configure.ac
> @@ -22,6 +23,8 @@ DHCP_CONF_ENV = \
>  		-D_PATH_DHCLIENT_CONF=\"/etc/dhcp/dhclient.conf\"' \
>  	CFLAGS='$(TARGET_CFLAGS) -DISC_CHECK_NONE=1'
>  
> +DHCP_CONF_ENV += ac_cv_prog_AWK=$(HOST_DIR)/bin/gawk
> +
>  DHCP_CONF_OPTS = \
>  	--with-libbind=$(STAGING_DIR)/usr \
>  	--with-randomdev=/dev/random \
>