Do not depend on Mono executables being in the PATH, but use prefix and system Mono paths to resolve them. Fixes El Capitan build issues.

The symlinks for the system Mono executables are installed in /usr/local/bin starting from OS X El Capitan, and we may no longer rely on them being part of the user's PATH. These changes prioritize using pkg-config to resolve their path, and look for pkg-config itself first in the F# install prefix, and then at the system Mono location. PATH is last resort.

This also properly isolates parallel installations from System Mono.

Author: alexischr

config.make.in

@@ -4,6 +4,7 @@ topdir := @abs_top_srcdir@/
 builddir := @abs_top_builddir@/
 libdir := ${prefix}/lib/
 bindir := ${prefix}/bin/
+monobindir := @MONOBINDIR@
 monolibdir := @MONOLIBDIR@
 monogacdir := @MONOGACDIR@
 

configure.ac

@@ -9,9 +9,13 @@ AC_PROG_MAKE_SET
 
 AC_PATH_PROG(PKG_CONFIG, pkg-config, no)
 
-# On OSX use Mono's private copy of pkg-config if it exists, see https://github.com/fsharp/fsharp/issues/107
+# pkg-config precedence: 1) our prefix 2) the system Mono location 3) the PATH
+prefix_pkg_config="$prefix"/bin/pkg-config
 osx_pkg_config=/Library/Frameworks/Mono.framework/Versions/Current/bin/pkg-config
-if test -e $osx_pkg_config; then
+
+if test -e $prefix_pkg_config; then
+    PKG_CONFIG=$prefix_pkg_config
+elif test -e $osx_pkg_config; then
     PKG_CONFIG=$osx_pkg_config
 elif test "x$PKG_CONFIG" = "xno"; then
         AC_MSG_ERROR([You need to install pkg-config])
@@ -20,18 +24,6 @@ fi
 AC_MSG_NOTICE("pkg-config: $PKG_CONFIG")
 AC_MSG_NOTICE("PKG_CONFIG_LIBDIR: $PKG_CONFIG_LIBDIR")
 
-# On OSX El Capitan, xbuild is no longer in PATH, so we need to use the full path.
-AC_PATH_PROG(XBUILD, xbuild, no)
-osx_xbuild=/Library/Frameworks/Mono.framework/Versions/Current/bin/xbuild
-if test "x$XBUILD" == "xno"; then
-  if test -e $osx_xbuild; then
-    XBUILD=$osx_xbuild
-  else
-    AC_MSG_ERROR([Could not find xbuild])
-  fi
-fi
-AC_MSG_NOTICE(xbuild: $XBUILD)
-
 MONO_REQUIRED_VERSION=3.0
 MONO_RECOMMENDED_VERSION=3.2
 
@@ -64,7 +56,18 @@ AC_ARG_WITH([gacdir],
         )
 
 MONOPREFIX=$(cd `$PKG_CONFIG --variable=prefix mono` && pwd)
+MONOBINDIR="$MONOPREFIX"/bin
 MONOLIBDIR="$MONOPREFIX"/lib
+
+AC_PATH_PROG(XBUILD, xbuild, no)
+xbuild_from_pkg_config="$MONOBINDIR"/xbuild
+if test -e $xbuild_from_pkg_config; then
+    XBUILD=$xbuild_from_pkg_config
+elif test "x$XBUILD" == "xno"; then
+    AC_MSG_ERROR([Could not find xbuild])
+fi
+AC_MSG_NOTICE(xbuild: $XBUILD)
+
 MONOGACDIR="$MONOLIBDIR"/mono
 if ! test "x$with_gacdir" = "xno"; then
 	MONOGACDIR=$(cd "$with_gacdir/.." && pwd)
@@ -138,6 +141,7 @@ AC_SUBST(MONOTOUCHENABLED)
 AC_SUBST(MONODROIDENABLED)
 AC_SUBST(XAMARINMACENABLED)
 
+AC_SUBST(MONOBINDIR)
 AC_SUBST(MONOLIBDIR)
 AC_SUBST(MONOGACDIR)
 

launcher.in

@@ -21,4 +21,4 @@ fi
 # location of the default FSharp install in order to find the FSharp compiler binaries (see 
 # fsharpbinding/MonoDevelop.FSharpBinding/Services/CompilerLocationUtils.fs). That's a pretty unfortunate
 # way of finding those binaries. And really should be changed.
-$EXEC mono $DEBUG $MONO_OPTIONS @DIR@/@TOOL@ --exename:$(basename "$0") "$@"
+$EXEC @MONOBINDIR@/mono $DEBUG $MONO_OPTIONS @DIR@/@TOOL@ --exename:$(basename "$0") "$@"

src/fsharp/policy.2.0.FSharp.Core/Makefile.in

@@ -14,7 +14,7 @@ include $(topdir)/src/fsharp/targets.make
 $(outdir)/$(NAME).dll: $(NAME).dll.config 
 	@mkdir -p $(@D)
 	cp $(NAME).dll.config $(@D)
-	al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
+	$(monobindir)/al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
 
 build: 
 	$(MAKE) $(outdir)/$(NAME).dll

src/fsharp/policy.2.3.FSharp.Core/Makefile.in

@@ -14,7 +14,7 @@ include $(topdir)/src/fsharp/targets.make
 $(outdir)/$(NAME).dll: $(NAME).dll.config 
 	@mkdir -p $(@D)
 	cp $(NAME).dll.config $(@D)
-	al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
+	$(monobindir)/al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
 
 build: 
 	$(MAKE) $(outdir)/$(NAME).dll

src/fsharp/policy.3.259.FSharp.Core/Makefile.in

@@ -14,7 +14,7 @@ include $(topdir)/src/fsharp/targets.make
 $(outdir)/$(NAME).dll: $(NAME).dll.config 
 	@mkdir -p $(@D)
 	cp $(NAME).dll.config $(@D)
-	al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
+	$(monobindir)/al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
 
 build: 
 	$(MAKE) $(outdir)/$(NAME).dll

src/fsharp/policy.3.3.FSharp.Core/Makefile.in

@@ -14,7 +14,7 @@ include $(topdir)/src/fsharp/targets.make
 $(outdir)/$(NAME).dll: $(NAME).dll.config 
 	@mkdir -p $(@D)
 	cp $(NAME).dll.config $(@D)
-	al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
+	$(monobindir)/al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
 
 build: 
 	$(MAKE) $(outdir)/$(NAME).dll

src/fsharp/policy.3.47.FSharp.Core/Makefile.in

@@ -14,7 +14,7 @@ include $(topdir)/src/fsharp/targets.make
 $(outdir)/$(NAME).dll: $(NAME).dll.config 
 	@mkdir -p $(@D)
 	cp $(NAME).dll.config $(@D)
-	al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
+	$(monobindir)/al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
 
 build: 
 	$(MAKE) $(outdir)/$(NAME).dll

src/fsharp/policy.3.7.FSharp.Core/Makefile.in

@@ -14,7 +14,7 @@ include $(topdir)/src/fsharp/targets.make
 $(outdir)/$(NAME).dll: $(NAME).dll.config 
 	@mkdir -p $(@D)
 	cp $(NAME).dll.config $(@D)
-	al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
+	$(monobindir)/al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
 
 build: 
 	$(MAKE) $(outdir)/$(NAME).dll

src/fsharp/policy.3.78.FSharp.Core/Makefile.in

@@ -14,7 +14,7 @@ include $(topdir)/src/fsharp/targets.make
 $(outdir)/$(NAME).dll: $(NAME).dll.config 
 	@mkdir -p $(@D)
 	cp $(NAME).dll.config $(@D)
-	al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
+	$(monobindir)/al /link:$(NAME).dll.config /out:$@ /delaysign /keyfile:$(topdir)msfinal.pub
 
 build: 
 	$(MAKE) $(outdir)/$(NAME).dll