- Issue #15484: Fix _PYTHON_PROJECT_BASE for srcdir != builddir builds;
  use _PYTHON_PROJECT_BASE in distutils/sysconfig.py.
diff --git a/configure.ac b/configure.ac
index 71bf871..fc8a68c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -65,7 +65,7 @@
 	    AC_MSG_ERROR([python$PACKAGE_VERSION interpreter not found])
 	fi
         AC_MSG_RESULT($interp)
-	PYTHON_FOR_BUILD="_PYTHON_PROJECT_BASE=$srcdir"' _PYTHON_HOST_PLATFORM=$(_PYTHON_HOST_PLATFORM) PYTHONPATH=$(srcdir)/Lib:$(srcdir)/Lib/plat-$(MACHDEP) '$interp
+	PYTHON_FOR_BUILD='_PYTHON_PROJECT_BASE=$(abs_builddir) _PYTHON_HOST_PLATFORM=$(_PYTHON_HOST_PLATFORM) PYTHONPATH=$(shell test -f pybuilddir.txt && echo $(abs_builddir)/`cat pybuilddir.txt`:)$(srcdir)/Lib:$(srcdir)/Lib/plat-$(MACHDEP) '$interp
     fi
 elif test "$cross_compiling" = maybe; then
     AC_MSG_ERROR([Cross compiling required --host=HOST-TUPLE and --build=ARCH])