--- a/m4/libxml2.m4	2020-05-10 19:36:06.000000000 +0200
+++ b/m4/libxml2.m4	2020-07-24 07:58:12.642619506 +0200
@@ -52,7 +52,7 @@
         AC_REQUIRE([PKG_PROG_PKG_CONFIG])
         PKG_PROG_PKG_CONFIG()
 
-        if test -x "$PKG_CONFIG"; then
+        if test -x $(which "$PKG_CONFIG"); then
 
             LIBXML2_CFLAGS="`$PKG_CONFIG --cflags libxml-2.0`"