build: add xargs as prerequisite

Build system needs an 'xargs' that supports '-r' which darwin doesn't.
Homebrew installs a 'gxargs' with the findutils package so look for
'gxargs' as well as 'xargs'

This is a bit of a 'fun' corner case anyway. xargs is only required by
the build if 'CONFIG_AUTOREMOVE' is set and after the build system has
built 'tools/findutils' we have a fully working xargs for host anyway.
Until that time we have to rely on the host's xargs implementation.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

diff --git a/include/prereq-build.mk b/include/prereq-build.mk
index a711ae33f7edd9d5ec494fc4d0e0e6a363a7ed85..6fec4c1a4a6c5866ce01c3228a3fa5122e4ddb2e 100644 (file)
--- a/include/prereq-build.mk
+++ b/include/prereq-build.mk
@@ -93,6 +93,11 @@ $(eval $(call SetupHostCommand,find,Please install GNU 'find', \
 $(eval $(call SetupHostCommand,bash,Please install GNU 'bash', \
        bash --version 2>&1 | grep GNU))
 
+$(eval $(call SetupHostCommand,xargs, \
+       Please install 'xargs' that supports '-r/--no-run-if-empty', \
+       gxargs -r --version, \
+       xargs -r --version))
+
 $(eval $(call SetupHostCommand,patch,Please install GNU 'patch', \
        gpatch --version 2>&1 | grep 'Free Software Foundation', \
        patch --version 2>&1 | grep 'Free Software Foundation'))