This port diff switches to using libc's MD5 implementation which I think should help. It creates a new patches/ directory, use "patch -E -p0" to apply it (then make clean; make repackage; make reinstall)..
Index: Makefile =================================================================== RCS file: /cvs/ports/audio/wavpack/Makefile,v retrieving revision 1.22 diff -u -p -r1.22 Makefile --- Makefile 1 Feb 2017 22:06:14 -0000 1.22 +++ Makefile 13 May 2017 21:54:58 -0000 @@ -3,6 +3,7 @@ COMMENT = audio codec for lossless, lossy and hybrid compression DISTNAME = wavpack-5.1.0 +REVISION = 0 CATEGORIES = audio HOMEPAGE = http://www.wavpack.com/ @@ -28,6 +29,9 @@ CONFIGURE_ENV = CPPFLAGS="-I${LOCALBASE LDFLAGS="-L${LOCALBASE}/lib" DOCDIR = ${PREFIX}/share/doc/wavpack + +pre-configure: + sed -i 's,#include "md5.h",#include <md5.h>,' ${WRKSRC}/cli/*.c post-install: ${INSTALL_DATA_DIR} ${DOCDIR} Index: patches/patch-cli_Makefile_in =================================================================== RCS file: patches/patch-cli_Makefile_in diff -N patches/patch-cli_Makefile_in --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ patches/patch-cli_Makefile_in 13 May 2017 21:54:58 -0000 @@ -0,0 +1,38 @@ +$OpenBSD$ + +Index: cli/Makefile.in +--- cli/Makefile.in.orig ++++ cli/Makefile.in +@@ -107,7 +107,7 @@ am__wavpack_SOURCES_DIST = wavpack.c riff.c wave64.c c + am_wavpack_OBJECTS = wavpack-wavpack.$(OBJEXT) wavpack-riff.$(OBJEXT) \ + wavpack-wave64.$(OBJEXT) wavpack-caff.$(OBJEXT) \ + wavpack-dsdiff.$(OBJEXT) wavpack-dsf.$(OBJEXT) \ +- wavpack-utils.$(OBJEXT) wavpack-md5.$(OBJEXT) \ ++ wavpack-utils.$(OBJEXT) \ + wavpack-import_id3.$(OBJEXT) $(am__objects_1) + wavpack_OBJECTS = $(am_wavpack_OBJECTS) + am__DEPENDENCIES_1 = +@@ -362,12 +362,12 @@ top_build_prefix = @top_build_prefix@ + top_builddir = @top_builddir@ + top_srcdir = @top_srcdir@ + wavpack_SOURCES = wavpack.c riff.c wave64.c caff.c dsdiff.c dsf.c \ +- utils.c md5.c import_id3.c $(am__append_1) ++ utils.c import_id3.c $(am__append_1) + wavpack_CFLAGS = $(AM_CFLAGS) $(ICONV_CFLAGS) -I$(top_srcdir)/include + @ENABLE_RPATH_TRUE@wavpack_LDFLAGS = -rpath $(libdir) + wavpack_LDADD = $(AM_LDADD) $(top_builddir)/src/.libs/libwavpack.la $(LIBM) $(ICONV_LIBS) + wvunpack_SOURCES = wvunpack.c riff.c wave64.c caff.c dsdiff.c dsf.c \ +- utils.c md5.c $(am__append_2) ++ utils.c $(am__append_2) + wvunpack_CFLAGS = $(AM_CFLAGS) $(ICONV_CFLAGS) -I$(top_srcdir)/include + @ENABLE_RPATH_TRUE@wvunpack_LDFLAGS = -rpath $(libdir) + wvunpack_LDADD = $(AM_LDADD) $(top_builddir)/src/.libs/libwavpack.la $(LIBM) $(ICONV_LIBS) +@@ -379,7 +379,7 @@ wvtag_SOURCES = wvtag.c utils.c import_id3.c $(am__app + wvtag_CFLAGS = $(AM_CFLAGS) -I$(top_srcdir)/include + @ENABLE_RPATH_TRUE@wvtag_LDFLAGS = -rpath $(libdir) + wvtag_LDADD = $(AM_LDADD) $(top_builddir)/src/.libs/libwavpack.la $(LIBM) $(ICONV_LIBS) +-@ENABLE_TESTS_TRUE@wvtest_SOURCES = wvtest.c md5.c ++@ENABLE_TESTS_TRUE@wvtest_SOURCES = wvtest.c + @ENABLE_TESTS_TRUE@wvtest_CFLAGS = $(AM_CFLAGS) -I$(top_srcdir)/include + @ENABLE_RPATH_TRUE@@ENABLE_TESTS_TRUE@wvtest_LDFLAGS = -rpath $(libdir) + @ENABLE_TESTS_TRUE@wvtest_LDADD = $(AM_LDADD) $(top_builddir)/src/.libs/libwavpack.la $(LIBM) -lpthread
