xbps-src-doinst-helper is run via fakeroot so set build vars before and after!

xbps-src/libexec/xbps-src-doinst-helper.sh.in

@@ -88,8 +88,6 @@ install_src_phase()
 			|| msg_error "can't change cwd to build_wrksrc!"
 	fi
 
-	set_build_vars
-
 	# Run pre_install func.
 	run_func pre_install 2>${wrksrc}/.xbps_pre_install.log
 	if [ $? -ne 0 ]; then
@@ -168,14 +166,12 @@ install_src_phase()
 		. $XBPS_SRCPKGDIR/${sourcepkg}/${subpkg}.template
 		pkgname=${subpkg}
 		set_tmpl_common_vars
-		set_build_vars
 		run_func do_install 2>${wrksrc}/.xbps_do_install_${pkgname}.log
 		if [ $? -ne 0 ]; then
 			msg_red "$pkgname: do_install() failed:"
 			cat ${wrksrc}/.xbps_do_install_${pkgname}.log
 			exit 1
 		fi
-		unset_build_vars
 	done
 
 	#
@@ -185,8 +181,6 @@ install_src_phase()
 		rm -rf $saved_wrksrc && \
 			msg_normal "Removed $sourcepkg-$lver build directory."
 	fi
-
-	unset_build_vars
 }
 
 #