golang: Avoid wrong hardcoded pkg-config path

Avoid having the value of the PKG_CONFIG environment variable at
build time being built into the go compiler. Fixes #3505.

packages/golang/build.sh

@@ -2,6 +2,7 @@ TERMUX_PKG_HOMEPAGE=https://golang.org/
 TERMUX_PKG_DESCRIPTION="Go programming language compiler"
 TERMUX_PKG_LICENSE="BSD 3-Clause"
 local _MAJOR_VERSION=1.12
+TERMUX_PKG_REVISION=1
 TERMUX_PKG_SHA256=09c43d3336743866f2985f566db0520b36f4992aea2b4b2fd9f52f17049e88f2
 # Use the ~ deb versioning construct in the future:
 TERMUX_PKG_VERSION=2:${_MAJOR_VERSION}
@@ -18,12 +19,15 @@ termux_step_make_install() {
 	mkdir -p $TERMUX_GODIR/{src,doc,lib,pkg/tool/$TERMUX_GOLANG_DIRNAME,pkg/include,pkg/${TERMUX_GOLANG_DIRNAME}}
 
 	cd $TERMUX_PKG_SRCDIR/src
+	# Unset PKG_CONFIG to avoid the path being hardcoded into src/cmd/cgo/zdefaultcc.go,
+	# see https://github.com/termux/termux-packages/issues/3505.
 	env CC_FOR_TARGET=$CC \
 	    CXX_FOR_TARGET=$CXX \
 	    CC=gcc \
 	    GO_LDFLAGS="-extldflags=-pie" \
 	    GOROOT_BOOTSTRAP=$GOROOT \
 	    GOROOT_FINAL=$TERMUX_GODIR \
+	    PKG_CONFIG= \
 	    ./make.bash
 
 	cd ..