go-build: fix build with new go-binary bootstrapped toolchain

We need to be more explicity in our exports and use of 'go' to
build properly with the new binary bootstrapped go toolchain.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

recipes-devtools/go/go-build/0001-build-use-instead-of-go.patch

@@ -0,0 +1,33 @@
+From 4db28c98481056c41097f808335c37e8517fe485 Mon Sep 17 00:00:00 2001
+From: Bruce Ashfield <bruce.ashfield@gmail.com>
+Date: Fri, 7 Aug 2020 23:39:18 -0400
+Subject: [PATCH] build: use  instead of 'go'
+
+While we can get away with 'go' if the host/target arch match, the
+new go-binary toolchain blows up in a cross compile situation.
+
+Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
+---
+ gobuild/Makefile | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/import/gobuild/Makefile b/src/import/gobuild/Makefile
+index 694d9ce..149d573 100644
+--- a/src/import/gobuild/Makefile
++++ b/src/import/gobuild/Makefile
+@@ -19,10 +19,10 @@ dep: ${GODEPPATHS}
+ 
+ ${GODEPPATHS}:
+ 	mkdir -p ${GOSRC}
+-	GOPATH=${GOPATH} go get $(subst ${GOSRC}/,,$@)
++	GOPATH=${GOPATH} ${GO} get $(subst ${GOSRC}/,,$@)
+ 
+ ${BIN}: ${GODEPPATHS} $(filter %/$@.go, ${MAIN})
+-	GOPATH=${GOPATH} ${ARCH} go build $(filter %/$@.go, ${MAIN})
++	GOPATH=${GOPATH} ${ARCH} ${GO} build $(filter %/$@.go, ${MAIN})
+ 
+ clean:
+ 	rm -f   ${BIN}
+-- 
+2.19.1
+

recipes-devtools/go/go-build_git.bb

@@ -8,6 +8,7 @@ SRCREV_runc = "e4363b038787addfa12e8b0acf5417d4fba01693"
 SRC_URI = "\
 	  git://github.com/lf-edge/runx;nobranch=1;name=runx \
 	  git://github.com/opencontainers/runc.git;nobranch=1;destsuffix=runc;name=runc \
+          file://0001-build-use-instead-of-go.patch \
 	  "
 SRC_URI[md5sum] = "0d701ac1e2a67d47ce7127432df2c32b"
 SRC_URI[sha256sum] = "5a26478906d5005f4f809402e981518d2b8844949199f60c4b6e1f986ca2a769"
@@ -34,9 +35,22 @@ do_compile() {
     export GOARCH="${TARGET_GOARCH}"
     cd ${S}/src/import/gobuild
     mkdir -p go/src/github.com/opencontainers
-    ln -s ${WORKDIR}/runc ${S}/src/import/gobuild/go/src/github.com/opencontainers/runc
+    ln -sf ${WORKDIR}/runc ${S}/src/import/gobuild/go/src/github.com/opencontainers/runc
     export GOPATH="${S}/src/import/gobuild/go/src/github.com/opencontainers/runc"
-    oe_runmake
+
+    # Build the target binaries
+    export GOARCH="${TARGET_GOARCH}"
+    # Pass the needed cflags/ldflags so that cgo can find the needed headers files and libraries
+    export CGO_ENABLED="1"
+    export CGO_CFLAGS="${CFLAGS} --sysroot=${STAGING_DIR_TARGET}"
+    export CGO_LDFLAGS="${LDFLAGS} --sysroot=${STAGING_DIR_TARGET}"
+    export CFLAGS=""
+    export LDFLAGS=""
+    export CC="${CC}"
+    export LD="${LD}"
+    export GOBIN=""
+
+    oe_runmake GO=${GO}
 }
 
 do_install() {