diff --git a/.github/workflows/mingw.yml b/.github/workflows/mingw.yml
deleted file mode 100644
index 0f9c9a2c5..000000000
--- a/.github/workflows/mingw.yml
+++ /dev/null
@@ -1,29 +0,0 @@
-name: NetCDF-Build MinGW
-on: [workflow_dispatch,push]
-
-jobs:
-  build:
-    runs-on: windows-latest
-    defaults:
-      run:
-        shell: msys2 {0}
-    steps:
-      - uses: actions/checkout@v2
-      - uses: msys2/setup-msys2@v2
-        with:
-          msystem: MINGW64
-          update: true
-          install: git mingw-w64-x86_64-toolchain automake libtool autoconf make mingw-w64-x86_64-hdf5 unzip
-      - name: CI-Build
-        shell: msys2 {0}
-        run: |
-          echo 'Running in MSYS2!'
-          set -e
-          pwd
-          git clone --single-branch --branch moreosfixes.tmp https://github.com/DennisHeimbigner/netcdf-c.git
-          cd netcdf-c
-          autoreconf -i --force
-          ./configure --prefix=/builddir -enable-shared  --disable-static --disable-plugins --disable-logging --disable-dap-remote-tests --disable-byterange
-          make -j LDFLAGS="-no-undefined  -Wl,--export-all-symbols"
-          make check
- 
diff --git a/.github/workflows/run_tests_win_mingw.yml b/.github/workflows/run_tests_win_mingw.yml
index 919c50f23..913920a3a 100644
--- a/.github/workflows/run_tests_win_mingw.yml
+++ b/.github/workflows/run_tests_win_mingw.yml
@@ -7,7 +7,7 @@
 name: Run MSYS2, MinGW64-based Tests
 
 
-on: [ pull_request ]
+on: [pull_request]
 
 jobs:
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4df431e47..c0065c0ee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1747,6 +1747,7 @@ CHECK_FUNCTION_EXISTS(strlcat   HAVE_STRLCAT)
 CHECK_FUNCTION_EXISTS(strdup  HAVE_STRDUP)
 CHECK_FUNCTION_EXISTS(strndup HAVE_STRNDUP)
 CHECK_FUNCTION_EXISTS(strtoll HAVE_STRTOLL)
+CHECK_FUNCTION_EXISTS(strcasecmp  HAVE_STRCASECMP)
 CHECK_FUNCTION_EXISTS(strtoull  HAVE_STRTOULL)
 CHECK_FUNCTION_EXISTS(mkstemp HAVE_MKSTEMP)
 CHECK_FUNCTION_EXISTS(mktemp HAVE_MKTEMP)
diff --git a/config.h.cmake.in b/config.h.cmake.in
index d16a7204b..1754b7508 100644
--- a/config.h.cmake.in
+++ b/config.h.cmake.in
@@ -346,12 +346,6 @@ are set when opening a binary file on Windows. */
 /* Define to 1 if you have the <stdlib.h> header file. */
 #cmakedefine HAVE_STDLIB_H 1
 
-/* Define to 1 if you have the `strdup' function. */
-#cmakedefine HAVE_STRDUP 1
-
-/* Define to 1 if you have the `strndup` function. */
-#cmakedefine HAVE_STRNDUP
-
 /* Define to 1 if you have the <strings.h> header file. */
 #cmakedefine HAVE_STRINGS_H 1
 
@@ -367,6 +361,15 @@ are set when opening a binary file on Windows. */
 /* Define to 1 if you have the <libgen.h> header file. */
 #cmakedefine HAVE_LIBGEN_H 1
 
+/* Define to 1 if you have the `strdup' function. */
+#cmakedefine HAVE_STRDUP 1
+
+/* Define to 1 if you have the `strndup` function. */
+#cmakedefine HAVE_STRNDUP
+
+/* Define to 1 if you have the `strcasecmp` function. */
+#cmakedefine HAVE_STRCASECMP
+
 /* Define to 1 if you have the `strlcat' function. */
 #cmakedefine HAVE_STRLCAT 1
 
diff --git a/configure.ac b/configure.ac
index a687c6036..fa7ebdf34 100644
--- a/configure.ac
+++ b/configure.ac
@@ -523,6 +523,45 @@ fi
 
 CFLAGS="$SAVECFLAGS"
 
+###
+# Libxml2 control block.
+###
+
+AC_MSG_CHECKING([whether to search for and use external libxml2])
+AC_ARG_ENABLE([libxml2],
+              [AS_HELP_STRING([--disable-libxml2],
+                              [disable detection and use of libxml2 in favor of the bundled ezxml interpreter])])
+test "x$enable_libxml2" = xno || enable_libxml2=yes
+AC_MSG_RESULT([$enable_libxml2])
+
+have_libxml2=no
+if test "x$enable_libxml2" = xyes; then
+  # We can optionally use libxml2 for DAP4, if available
+  AC_CHECK_LIB([xml2],[xmlReadMemory],[have_libxml2=yes],[have_libxml2=no])
+  if test "x$have_libxml2" = "xyes" ; then
+      AC_SEARCH_LIBS([xmlReadMemory],[xml2 xml2.dll cygxml2.dll], [],[])
+  fi
+  if test "x$have_libxml2" = xyes; then
+     XML2FLAGS=`xml2-config --cflags`
+     AC_SUBST([XML2FLAGS],${XML2FLAGS})
+     AC_DEFINE([HAVE_LIBXML2], [1], [if true, use libxml2])
+  fi
+fi
+
+if test "x$enable_libxml2" = xyes; then
+XMLPARSER="libxml2"
+else
+XMLPARSER="tinyxml2 (bundled)"
+fi
+
+# Need a condition and subst for this
+AM_CONDITIONAL(ENABLE_LIBXML2, [test "x$enable_libxml2" = xyes])
+AC_SUBST([XMLPARSER],[${XMLPARSER}])
+
+###
+# End Libxml2 block
+###
+
 # --enable-dap => enable-dap4
 enable_dap4=$enable_dap
 AC_MSG_CHECKING([whether dap remote testing should be enabled])
@@ -1046,55 +1085,21 @@ AC_CHECK_FUNCS([strlcat snprintf strcasecmp fileno \
 AC_CHECK_FUNCS([clock_gettime])
 AC_CHECK_TYPES([struct timespec])
 
-# disable dap4 if netcdf-4 is disabled
-#if test "x$enable_netcdf_4" = "xno" ; then
+# disable dap4 if hdf5 is disabled
 if test "x$enable_hdf5" = "xno" ; then
     AC_MSG_WARN([netcdf-4 not enabled; disabling DAP4])
     enable_dap4=no
 fi
 
+if test "x$ISOSX" = xyes && "x$have_libxml2" = xno ; then
+  AC_MSG_ERROR([Error: OSX requires libxml2 => --disable-dap4.])
+  enable_dap4=no
+fi
+
 if test "x$enable_dap4" = xyes; then
    AC_DEFINE([ENABLE_DAP4], [1], [if true, build DAP4 Client])
 fi
 
-###
-# Libxml2 control block.
-###
-
-AC_MSG_CHECKING([whether to search for and use external libxml2])
-AC_ARG_ENABLE([libxml2],
-              [AS_HELP_STRING([--disable-libxml2],
-                              [disable detection and use of libxml2 in favor of the bundled ezxml interpreter])])
-test "x$enable_libxml2" = xno && enable_libxml2=yes
-AC_MSG_RESULT($enable_libxml2)
-
-if test "x$enable_libxml2" = xyes; then
-  # We can optionally use libxml2 for DAP4, if available
-  AC_CHECK_LIB([xml2],[xmlReadMemory],[have_libxml2=yes],[have_libxml2=no])
-  if test "x$have_libxml2" = "xyes" ; then
-      AC_SEARCH_LIBS([xmlReadMemory],[xml2 xml2.dll cygxml2.dll], [],[])
-  fi
-  if test "x$have_libxml2" = xyes; then
-     XML2FLAGS=`xml2-config --cflags`
-     AC_SUBST([XML2FLAGS],${XML2FLAGS})
-     AC_DEFINE([HAVE_LIBXML2], [1], [if true, use libxml2])
-  fi
-fi
-
-if test "x$enable_libxml2" = xyes; then
-XMLPARSER="libxml2"
-else
-XMLPARSER="tinyxml2 (bundled)"
-fi
-
-# Need a condition and subst for this
-AM_CONDITIONAL(ENABLE_LIBXML2, [test "x$enable_libxml2" = xyes])
-AC_SUBST([XMLPARSER],[${XMLPARSER}])
-
-###
-# End Libxml2 block
-###
-
 # check for useful, but not essential, memio support
 AC_CHECK_FUNCS([memmove getpagesize sysconf])
 
diff --git a/dap4_test/Makefile.am b/dap4_test/Makefile.am
index 910783e64..ec5623094 100644
--- a/dap4_test/Makefile.am
+++ b/dap4_test/Makefile.am
@@ -10,6 +10,7 @@ include $(top_srcdir)/lib_flags.am
 #SH_LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
 #LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
 #TEST_LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
+#TESTS_ENVIRONMENT = export SETX=1;
 
 # Note which tests depend on other tests. Necessary for make -j check.
 TEST_EXTENSIONS = .sh
diff --git a/dap4_test/test_data.c b/dap4_test/test_data.c
index 137d46e1e..000eca485 100644
--- a/dap4_test/test_data.c
+++ b/dap4_test/test_data.c
@@ -44,7 +44,7 @@ main(int argc, char** argv)
     snprintf(url,sizeof(url),"file://%s#dap4&debug=copy%s%s%s",
 	argv[0],
         (argc >= 3 ? "&substratename=" : ""),
-        (argc >= 3 ? "argv[1]" : ""),
+        (argc >= 3 ? argv[1] : ""),
 #ifdef DEBUG
 	"&log"
 #else
diff --git a/include/ncconfigure.h b/include/ncconfigure.h
index 3cc76cab0..cde14a94d 100644
--- a/include/ncconfigure.h
+++ b/include/ncconfigure.h
@@ -70,7 +70,7 @@ int snprintf(char*, size_t, const char*, ...);
 
 #ifndef HAVE_STRCASECMP
 #ifndef strcasecmp
-int strcasecmp(const char*, const char*);
+extern int strcasecmp(const char*, const char*);
 #endif
 #endif
 
diff --git a/libncxml/Makefile.am b/libncxml/Makefile.am
index 2156e560e..3866eae5b 100644
--- a/libncxml/Makefile.am
+++ b/libncxml/Makefile.am
@@ -29,12 +29,13 @@ endif
 
 EXTRA_DIST = CMakeLists.txt license.txt
 
-# Download the tinyxml2 source
+# Download and massage the tinyxml2 source
 REPO = https://github.com/leethomason/tinyxml2.git
 tinyxml2::
 	rm -fr ./tinyxml2 ./license.txt
 	git clone --depth=1 ${REPO}
 	cat tinyxml2/LICENSE.txt > ./license.txt
 	cat tinyxml2/tinyxml2.h > ./tinyxml2.h
-	cat tinyxml2/tinyxml2.cpp > ./tinyxml2.cpp
+	sed -e 's/__BORLANDC__/__APPLE__/' < tinyxml2/tinyxml2.cpp \
+	| sed -e 's/ptrdiff_t/long/g' > ./tinyxml2.cpp
 	rm -fr tinyxml2
diff --git a/libncxml/tinyxml2.cpp b/libncxml/tinyxml2.cpp
index 3cbe174c0..dd7bdca32 100644
--- a/libncxml/tinyxml2.cpp
+++ b/libncxml/tinyxml2.cpp
@@ -24,7 +24,7 @@ distribution.
 #include "tinyxml2.h"
 
 #include <new>		// yes, this one new style header, is in the Android SDK.
-#if defined(ANDROID_NDK) || defined(__BORLANDC__) || defined(__QNXNTO__)
+#if defined(ANDROID_NDK) || defined(__APPLE__) || defined(__QNXNTO__)
 #   include <stddef.h>
 #   include <stdarg.h>
 #else
@@ -476,7 +476,7 @@ const char* XMLUtil::GetCharacterRef( const char* p, char* value, int* length )
     if ( *(p+1) == '#' && *(p+2) ) {
         unsigned long ucs = 0;
         TIXMLASSERT( sizeof( ucs ) >= 4 );
-        ptrdiff_t delta = 0;
+        long delta = 0;
         unsigned mult = 1;
         static const char SEMICOLON = ';';
 
diff --git a/ncdump/tst_nccopy4.sh b/ncdump/tst_nccopy4.sh
index 7b482a78b..81493b038 100755
--- a/ncdump/tst_nccopy4.sh
+++ b/ncdump/tst_nccopy4.sh
@@ -7,7 +7,6 @@ set -e
 
 # For a netCDF-4 build, test nccopy on netCDF files in this directory
 
-echo "@@@@@@"
 if test -f tst_group_data${ext} ; then ${execdir}/tst_group_data ; fi
 if test -f tst_enum_data${ext} ; then ${execdir}/tst_enum_data ; fi
 if test -f tst_comp${ext} ; then ${execdir}/tst_comp ; fi
diff --git a/nczarr_test/run_filter.sh b/nczarr_test/run_filter.sh
index 08ce36d0a..78e3f0a7f 100755
--- a/nczarr_test/run_filter.sh
+++ b/nczarr_test/run_filter.sh
@@ -60,9 +60,6 @@ MISCPATH="${HDF5_PLUGIN_PATH}/${HDF5_PLUGIN_LIB}"
 if ! test -f ${BZIP2PATH} ; then echo "Unable to locate ${BZIP2PATH}"; exit 1; fi
 if ! test -f ${MISCPATH} ; then echo "Unable to locate ${MISCPATH}"; exit 1; fi
 
-echo "@@@@@@@@@@@"
-find ${HDF5_PLUGIN_PATH}
-
 # Execute the specified tests
 
 testapi() {