The included libtool is broken and loses the -lm dependency_lib.

--- lib/Makefile.in.orig	2020-07-11 16:57:29 UTC
+++ lib/Makefile.in
@@ -461,7 +461,7 @@ libvorbis_la_LDFLAGS = -no-undefined -version-info @V_
 libvorbis_la_LIBADD = @VORBIS_LIBS@ @OGG_LIBS@
 libvorbisfile_la_SOURCES = vorbisfile.c
 libvorbisfile_la_LDFLAGS = -no-undefined -version-info @VF_LIB_CURRENT@:@VF_LIB_REVISION@:@VF_LIB_AGE@
-libvorbisfile_la_LIBADD = libvorbis.la @OGG_LIBS@
+libvorbisfile_la_LIBADD = libvorbis.la @OGG_LIBS@ -lm
 libvorbisenc_la_SOURCES = vorbisenc.c 
 libvorbisenc_la_LDFLAGS = -no-undefined -version-info @VE_LIB_CURRENT@:@VE_LIB_REVISION@:@VE_LIB_AGE@
 libvorbisenc_la_LIBADD = libvorbis.la @OGG_LIBS@