I believe this works now. I am able to compile and run some C# apps included

in the mono/tests/ subdirectory, and it no longer hangs or dies with weird
errors.  (And, yes, I do have garbage collecting enabled).

I'll let the C# user community be my judge.  There still may be some issues
since boehm-gc isn't fully functional in its multi-threaded state on FreeBSD.

lang/mono/Makefile

@@ -7,21 +7,22 @@
 
 PORTNAME=	mono
 PORTVERSION=	0.28
+PORTREVISION=	1
 CATEGORIES=	lang
 MASTER_SITES=	http://www.go-mono.com/archive/
 
 MAINTAINER=	gnome@FreeBSD.org
 COMMENT=	An open source implementation of .NET Development Framework
 
-LIB_DEPENDS=	gc.1:${PORTSDIR}/devel/boehm-gc
-
 USE_LIBTOOL=	yes
 USE_REINPLACE=	yes
 USE_BISON=	yes
 USE_GNOME=	gnomehack glib20 pkgconfig
 USE_GMAKE=	yes
+LIBTOOLFILES=	configure libgc/configure
 INSTALLS_SHLIB=	yes
-CONFIGURE_ARGS=	--program-transform-name=\'\'
+CONFIGURE_ARGS=	--program-transform-name=\'\' \
+		--with-gc=included
 CONFIGURE_ENV=	CPPFLAGS="-I${LOCALBASE}/include" \
 		LDFLAGS="-L${LOCALBASE}/lib"
 
@@ -32,4 +33,14 @@ MAN5=		mono-config.5
 
 ONLY_FOR_ARCHS=	i386
 
-.include <bsd.port.mk>
+.include <bsd.port.pre.mk>
+
+.if ${OSVERSION} < 500000
+EXTRA_PATCHES=	${FILESDIR}/extra-patch-signbit
+.endif
+
+post-patch:
+	@${REINPLACE_CMD} -e 's|-pthread|${PTHREAD_LIBS}|g' \
+		${WRKSRC}/configure
+
+.include <bsd.port.post.mk>

lang/mono/files/extra-patch-signbit

@@ -0,0 +1,35 @@
+--- mono/mini/mini-x86.c	Mon Sep 29 05:28:49 2003
++++ mono/mini/mini-x86.c	Sat Aug 30 04:01:27 2003
+@@ -40,6 +40,32 @@
+ 	guint8  pad;
+ } MonoJitArgumentInfo;
+ 
++union IEEEd2bits {
++    double d;
++    struct {
++#if _BYTE_ORDER == _LITTLE_ENDIAN
++	unsigned int    manl    :32;
++	unsigned int    manh    :20;
++	unsigned int    exp     :11;
++	unsigned int    sign    :1;
++#else
++	unsigned int    sign    :1;
++	unsigned int    exp     :11;
++	unsigned int    manh    :20;
++	unsigned int    manl    :32;
++#endif
++    } bits;
++};
++
++int
++signbit(double d)
++{
++    union IEEEd2bits u;
++
++    u.d = d;
++    return (u.bits.sign);
++}
++
+ /*
+  * arch_get_argument_info:
+  * @csig:  a method signature

lang/mono/files/patch-configure

@@ -1,6 +1,15 @@
---- configure.orig	Thu Dec 26 13:09:19 2002
-+++ configure	Thu Dec 26 13:09:37 2002
-@@ -7501,6 +7501,7 @@
+--- configure.orig	Wed Oct  1 12:59:06 2003
++++ configure	Mon Oct  6 23:25:13 2003
+@@ -2005,7 +2005,7 @@
+ _ACEOF
+ 
+ 		libdl=
+-		libgc_threads=pthreads
++		libgc_threads=no
+ 		;;
+ 	*-*-linux*)
+ 		platform_win32=no
+@@ -8257,6 +8257,7 @@
  
  # This can be used to rebuild libtool when needed
  LIBTOOL_DEPS="$ac_aux_dir/ltmain.sh"

lang/mono/files/patch-libgc_configure

@@ -0,0 +1,10 @@
+--- libgc/configure.orig	Thu Dec 26 13:09:19 2002
++++ libgc/configure	Thu Dec 26 13:09:37 2002
+@@ -7501,6 +7501,7 @@
+ 
+ # This can be used to rebuild libtool when needed
+ LIBTOOL_DEPS="$ac_aux_dir/ltmain.sh"
++$ac_aux_dir/ltconfig $LIBTOOL_DEPS
+ 
+ # Always use our own libtool.
+ LIBTOOL='$(SHELL) $(top_builddir)/libtool'

lang/mono/files/patch-libgc_include_private_gcconfig.h

@@ -0,0 +1,24 @@
+--- libgc/include/private/gcconfig.h.orig	Mon Oct  6 22:38:35 2003
++++ libgc/include/private/gcconfig.h	Mon Oct  6 22:38:56 2003
+@@ -1151,8 +1151,8 @@
+ #	ifndef GC_FREEBSD_THREADS
+ #	    define MPROTECT_VDB
+ #	endif
+-#	define SIG_SUSPEND SIGUSR1
+-#	define SIG_THR_RESTART SIGUSR2
++#	define SIG_SUSPEND SIGTSTP
++#	define SIG_THR_RESTART SIGCONT
+ #	define FREEBSD_STACKBOTTOM
+ #	ifdef __ELF__
+ #	    define DYNAMIC_LOADING
+@@ -1466,8 +1466,8 @@
+ #   ifdef FREEBSD
+ #	define OS_TYPE "FREEBSD"
+ /* MPROTECT_VDB is not yet supported at all on FreeBSD/alpha. */
+-#	define SIG_SUSPEND SIGUSR1
+-#	define SIG_THR_RESTART SIGUSR2
++#	define SIG_SUSPEND SIGTSTP
++#	define SIG_THR_RESTART SIGCONT
+ #	define FREEBSD_STACKBOTTOM
+ #	ifdef __ELF__
+ #	    define DYNAMIC_LOADING