[aisleriot] Support guile 2.0

[Christian Persch <chpe src gnome org>]

commit 57f08c221d6ebe7f165652762f542a11adac6a43
Author: Christian Persch <chpe gnome org>
Date:   Tue Apr 12 23:03:22 2011 +0200

    Support guile 2.0
    
    Bug #630334.

 configure.ac |   14 +++++++++++++-
 src/game.c   |    4 ++--
 2 files changed, 15 insertions(+), 3 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 632dc35..92da707 100644
--- a/configure.ac
+++ b/configure.ac
@@ -513,8 +513,20 @@ IT_PROG_INTLTOOL([0.35.0])
 # *****
 
 GUILE_1_8_REQUIRED=1.8.0
+GUILE_2_0_REQUIRED=2.0.0
+GUILE_2_2_REQUIRED=2.0.0
 
-PKG_CHECK_MODULES([GUILE],[guile-1.8 >= $GUILE_1_8_REQUIRED])
+GUILE_PKGS=
+
+AC_MSG_CHECKING([for guile version])
+PKG_CHECK_EXISTS([guile-2.2 >= $GUILE_2_2_REQUIRED],
+  [GUILE_API_VERSION="2.2" GUILE_PKGS="guile-2.2 >= $GUILE_2_2_REQUIRED"],
+  [PKG_CHECK_EXISTS([guile-2.0 >= $GUILE_2_0_REQUIRED],
+    [GUILE_API_VERSION="2.0" GUILE_PKGS="guile-2.0 >= $GUILE_2_0_REQUIRED"],
+    [GUILE_API_VERSION="1.8" GUILE_PKGS="guile-1.8 >= $GUILE_1_8_REQUIRED"])])
+AC_MSG_RESULT([$GUILE_API_VERSION])
+
+PKG_CHECK_MODULES([GUILE],[$GUILE_PKGS])
 
 # *************
 # Documentation
diff --git a/src/game.c b/src/game.c
index 461fc67..03e96af 100644
--- a/src/game.c
+++ b/src/game.c
@@ -317,8 +317,8 @@ cscmi_exception_get_backtrace (SCM tag, SCM throw_args)
   free (string);
 
   g_string_append (message, "\n\nBacktrace:\n");
-  stack = scm_fluid_ref (SCM_VARIABLE_REF (scm_the_last_stack_fluid_var));
-  if (!SCM_FALSEP (stack)) {
+  stack = scm_make_stack (SCM_BOOL_T, SCM_EOL);
+  if (!scm_is_false (stack)) {
     scm_display_backtrace (stack, port, SCM_UNDEFINED, SCM_UNDEFINED);
     string = scm_to_locale_string (scm_get_output_string (port));
     g_string_append (message, string);