Some platforms don't support the long options for mkdir.  Seems there
is a variable, MKDIR_P, set by Autoconf that is used elsewhere in the
Emacs build system that could be used instead.  Patch is attached and
quoted below.

Thanks,
Aaron

---
 test/Makefile.in | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/Makefile.in b/test/Makefile.in
index b5954df..beb3ff9 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -29,6 +29,7 @@
 ### Code:

 SHELL = @SHELL@
+MKDIR_P = @MKDIR_P@

 srcdir = @srcdir@
 VPATH = $(srcdir)
@@ -110,7 +111,7 @@ endif
  fi; \
  echo Testing $$loadfile; \
  stat=OK ; \
- mkdir --parents $(dir $@) ; \
+ ${MKDIR_P} $(dir $@) ; \
  $(emacs) -l ert -l $$loadfile \
   --eval "(ert-run-tests-batch-and-exit ${SELECTOR_ACTUAL})" ${WRITE_LOG}

--