With MSVC/clang, I'm seeing this configure output:
checking whether realpath works... mkdir: cannot create directory
'conftest.d': File exists
no
The .d files contain dependency information, apparently generated by clang.
So, we need to clean up before starting the test.
2020-08-15 Bruno Haible <br...@clisp.org>
canonicalize: Fix a problem of the autoconf test on MSVC/clang.
* m4/canonicalize.m4 (gl_FUNC_REALPATH_WORKS): Remove undesired file
from dependency analysis first.
diff --git a/m4/canonicalize.m4 b/m4/canonicalize.m4
index de64cf7..14ea3e1 100644
--- a/m4/canonicalize.m4
+++ b/m4/canonicalize.m4
@@ -1,4 +1,4 @@
-# canonicalize.m4 serial 32
+# canonicalize.m4 serial 33
dnl Copyright (C) 2003-2007, 2009-2020 Free Software Foundation, Inc.
@@ -79,6 +79,7 @@ AC_DEFUN([gl_FUNC_REALPATH_WORKS],
AC_CHECK_FUNCS_ONCE([realpath])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether realpath works], [gl_cv_func_realpath_works], [
+ rm -rf conftest.a conftest.d
touch conftest.a
mkdir conftest.d
AC_RUN_IFELSE([
