X-Git-Url: http://nitlanguage.org

diff --git a/c_src/toolcontext.sep.1.c b/c_src/toolcontext.sep.1.c
index b5cb7c2..da998c4 100644
--- a/c_src/toolcontext.sep.1.c
+++ b/c_src/toolcontext.sep.1.c
@@ -33,8 +33,9 @@ val* var /* : String */;
 val* var1 /* : String */;
 var1 = self->attrs[COLOR_toolcontext__Message___64dtext].val; /* @text on <self:Message> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @text", "src/toolcontext.nit", 30);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @text");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 30);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -66,6 +67,7 @@ short int var1 /* : Bool */;
 int cltype;
 int idtype;
 const struct type* type_struct;
+const char* var_class_name;
 val* var_other /* var other: Message */;
 val* var2 /* : nullable Location */;
 val* var3 /* : null */;
@@ -89,8 +91,10 @@ var1 = 0;
 var1 = p0->type->type_table[cltype] == idtype;
 }
 if (!var1) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Cast failed", "src/toolcontext.nit", 32);
-exit(1);
+var_class_name = p0 == NULL ? "null" : p0->type->name;
+fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name);
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 32);
+show_backtrace(1);
 }
 var_other = p0;
 var2 = ((val* (*)(val*))(self->class->vft[COLOR_toolcontext__Message__location]))(self) /* location on <self:Message>*/;
@@ -121,13 +125,15 @@ goto RET_LABEL;
 }
 var10 = ((val* (*)(val*))(self->class->vft[COLOR_toolcontext__Message__location]))(self) /* location on <self:Message>*/;
 if (var10 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Cast failed", "src/toolcontext.nit", 37);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Cast failed");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 37);
+show_backtrace(1);
 }
 var11 = ((val* (*)(val*))(var_other->class->vft[COLOR_toolcontext__Message__location]))(var_other) /* location on <var_other:Message>*/;
 if (var11 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Cast failed", "src/toolcontext.nit", 37);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Cast failed");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 37);
+show_backtrace(1);
 }
 var12 = ((short int (*)(val*, val*))(var10->class->vft[COLOR_kernel__Comparable___60d]))(var10, var11) /* < on <var10:nullable Location(Location)>*/;
 var = var12;
@@ -188,7 +194,6 @@ goto RET_LABEL;
 var5 = NEW_array__Array(&type_array__Arraykernel__Object);
 var6 = 5;
 ((void (*)(val*, long))(var5->class->vft[COLOR_array__Array__with_capacity]))(var5, var6) /* with_capacity on <var5:Array[Object]>*/;
-CHECK_NEW_array__Array(var5);
 var_ = var5;
 if (varonce) {
 var7 = varonce;
@@ -416,7 +421,6 @@ var_esc = var2;
 var5 = NEW_array__Array(&type_array__Arraykernel__Object);
 var6 = 3;
 ((void (*)(val*, long))(var5->class->vft[COLOR_array__Array__with_capacity]))(var5, var6) /* with_capacity on <var5:Array[Object]>*/;
-CHECK_NEW_array__Array(var5);
 var_ = var5;
 if (varonce) {
 var7 = varonce;
@@ -445,7 +449,6 @@ var_red = var17;
 var18 = NEW_array__Array(&type_array__Arraykernel__Object);
 var19 = 3;
 ((void (*)(val*, long))(var18->class->vft[COLOR_array__Array__with_capacity]))(var18, var19) /* with_capacity on <var18:Array[Object]>*/;
-CHECK_NEW_array__Array(var18);
 var_20 = var18;
 if (varonce21) {
 var22 = varonce21;
@@ -474,7 +477,6 @@ var_bred = var32;
 var33 = NEW_array__Array(&type_array__Arraykernel__Object);
 var34 = 3;
 ((void (*)(val*, long))(var33->class->vft[COLOR_array__Array__with_capacity]))(var33, var34) /* with_capacity on <var33:Array[Object]>*/;
-CHECK_NEW_array__Array(var33);
 var_35 = var33;
 if (varonce36) {
 var37 = varonce36;
@@ -503,7 +505,6 @@ var_green = var47;
 var48 = NEW_array__Array(&type_array__Arraykernel__Object);
 var49 = 3;
 ((void (*)(val*, long))(var48->class->vft[COLOR_array__Array__with_capacity]))(var48, var49) /* with_capacity on <var48:Array[Object]>*/;
-CHECK_NEW_array__Array(var48);
 var_50 = var48;
 if (varonce51) {
 var52 = varonce51;
@@ -532,7 +533,6 @@ var_yellow = var62;
 var63 = NEW_array__Array(&type_array__Arraykernel__Object);
 var64 = 3;
 ((void (*)(val*, long))(var63->class->vft[COLOR_array__Array__with_capacity]))(var63, var64) /* with_capacity on <var63:Array[Object]>*/;
-CHECK_NEW_array__Array(var63);
 var_65 = var63;
 if (varonce66) {
 var67 = varonce66;
@@ -582,7 +582,6 @@ if (var84){
 var85 = NEW_array__Array(&type_array__Arraykernel__Object);
 var86 = 9;
 ((void (*)(val*, long))(var85->class->vft[COLOR_array__Array__with_capacity]))(var85, var86) /* with_capacity on <var85:Array[Object]>*/;
-CHECK_NEW_array__Array(var85);
 var_87 = var85;
 if (varonce88) {
 var89 = varonce88;
@@ -646,7 +645,6 @@ goto RET_LABEL;
 var115 = NEW_array__Array(&type_array__Arraykernel__Object);
 var116 = 11;
 ((void (*)(val*, long))(var115->class->vft[COLOR_array__Array__with_capacity]))(var115, var116) /* with_capacity on <var115:Array[Object]>*/;
-CHECK_NEW_array__Array(var115);
 var_117 = var115;
 if (varonce118) {
 var119 = varonce118;
@@ -814,8 +812,9 @@ val* var /* : String */;
 val* var1 /* : String */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dlog_directory].val; /* @log_directory on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @log_directory", "src/toolcontext.nit", 78);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @log_directory");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 78);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -846,8 +845,9 @@ val* var /* : Array[Message] */;
 val* var1 /* : Array[Message] */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dmessages].val; /* @messages on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @messages", "src/toolcontext.nit", 81);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @messages");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 81);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -878,8 +878,9 @@ val* var /* : ComparableSorter[Message] */;
 val* var1 /* : ComparableSorter[Message] */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dmessage_sorter].val; /* @message_sorter on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @message_sorter", "src/toolcontext.nit", 83);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @message_sorter");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 83);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -913,6 +914,7 @@ short int var3 /* : Bool */;
 short int var5 /* : Bool */;
 int cltype;
 int idtype;
+const char* var_class_name;
 short int var6 /* : Bool */;
 val* var7 /* : ComparableSorter[Message] */;
 val* var8 /* : Array[Message] */;
@@ -952,8 +954,9 @@ short int var39 /* : Bool */;
 short int var41 /* : Bool */;
 int cltype42;
 int idtype43;
-short int var44 /* : Bool */;
-long var45 /* : Int */;
+const char* var_class_name44;
+short int var45 /* : Bool */;
+long var46 /* : Int */;
 var = ((val* (*)(val*))(self->class->vft[COLOR_toolcontext__ToolContext__messages]))(self) /* messages on <self:ToolContext>*/;
 var1 = ((long (*)(val*))(var->class->vft[COLOR_abstract_collection__Collection__length]))(var) /* length on <var:Array[Message]>*/;
 var2 = 0;
@@ -962,8 +965,10 @@ var2 = 0;
 /* <var2:Int> isa OTHER */
 var5 = 1; /* easy <var2:Int> isa OTHER*/
 if (!var5) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Cast failed", "lib/standard/kernel.nit", 259);
-exit(1);
+var_class_name = type_kernel__Int.name;
+fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name);
+fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 267);
+show_backtrace(1);
 }
 var6 = var1 > var2;
 var3 = var6;
@@ -1002,7 +1007,6 @@ var23 = NEW_array__NativeArray(var22, &type_array__NativeArraykernel__Object);
 ((struct instance_array__NativeArray*)var23)->values[0] = (val*) var_m;
 ((struct instance_array__NativeArray*)var23)->values[1] = (val*) var17;
 ((void (*)(val*, val*, long))(var21->class->vft[COLOR_array__Array__with_native]))(var21, var23, var22) /* with_native on <var21:Array[Object]>*/;
-CHECK_NEW_array__Array(var21);
 }
 var24 = ((val* (*)(val*))(var21->class->vft[COLOR_string__Object__to_s]))(var21) /* to_s on <var21:Array[Object]>*/;
 ((void (*)(val*, val*))(var16->class->vft[COLOR_stream__OStream__write]))(var16, var24) /* write on <var16:OFStream>*/;
@@ -1025,7 +1029,6 @@ var34 = NEW_array__NativeArray(var33, &type_array__NativeArraykernel__Object);
 ((struct instance_array__NativeArray*)var34)->values[0] = (val*) var26;
 ((struct instance_array__NativeArray*)var34)->values[1] = (val*) var28;
 ((void (*)(val*, val*, long))(var32->class->vft[COLOR_array__Array__with_native]))(var32, var34, var33) /* with_native on <var32:Array[Object]>*/;
-CHECK_NEW_array__Array(var32);
 }
 var35 = ((val* (*)(val*))(var32->class->vft[COLOR_string__Object__to_s]))(var32) /* to_s on <var32:Array[Object]>*/;
 ((void (*)(val*, val*))(var25->class->vft[COLOR_stream__OStream__write]))(var25, var35) /* write on <var25:OFStream>*/;
@@ -1045,17 +1048,19 @@ var38 = 0;
 /* <var38:Int> isa OTHER */
 var41 = 1; /* easy <var38:Int> isa OTHER*/
 if (!var41) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Cast failed", "lib/standard/kernel.nit", 259);
-exit(1);
+var_class_name44 = type_kernel__Int.name;
+fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name44);
+fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 267);
+show_backtrace(1);
 }
-var44 = var37 > var38;
-var39 = var44;
+var45 = var37 > var38;
+var39 = var45;
 goto RET_LABEL40;
 RET_LABEL40:(void)0;
 }
 if (var39){
-var45 = 1;
-((void (*)(val*, long))(self->class->vft[COLOR_kernel__Object__exit]))(self, var45) /* exit on <self:ToolContext>*/;
+var46 = 1;
+((void (*)(val*, long))(self->class->vft[COLOR_kernel__Object__exit]))(self, var46) /* exit on <self:ToolContext>*/;
 } else {
 }
 RET_LABEL:;
@@ -1083,7 +1088,6 @@ var_s = p1;
 var = ((val* (*)(val*))(self->class->vft[COLOR_toolcontext__ToolContext__messages]))(self) /* messages on <self:ToolContext>*/;
 var1 = NEW_toolcontext__Message(&type_toolcontext__Message);
 ((void (*)(val*, val*, val*))(var1->class->vft[COLOR_toolcontext__Message__init]))(var1, var_l, var_s) /* init on <var1:Message>*/;
-CHECK_NEW_toolcontext__Message(var1);
 ((void (*)(val*, val*))(var->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var, var1) /* add on <var:Array[Message]>*/;
 var2 = ((long (*)(val*))(self->class->vft[COLOR_toolcontext__ToolContext__error_count]))(self) /* error_count on <self:ToolContext>*/;
 var3 = 1;
@@ -1164,7 +1168,6 @@ goto RET_LABEL;
 var7 = ((val* (*)(val*))(self->class->vft[COLOR_toolcontext__ToolContext__messages]))(self) /* messages on <self:ToolContext>*/;
 var8 = NEW_toolcontext__Message(&type_toolcontext__Message);
 ((void (*)(val*, val*, val*))(var8->class->vft[COLOR_toolcontext__Message__init]))(var8, var_l, var_s) /* init on <var8:Message>*/;
-CHECK_NEW_toolcontext__Message(var8);
 ((void (*)(val*, val*))(var7->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var7, var8) /* add on <var7:Array[Message]>*/;
 var9 = ((long (*)(val*))(self->class->vft[COLOR_toolcontext__ToolContext__warning_count]))(self) /* warning_count on <self:ToolContext>*/;
 var10 = 1;
@@ -1198,6 +1201,7 @@ short int var1 /* : Bool */;
 short int var3 /* : Bool */;
 int cltype;
 int idtype;
+const char* var_class_name;
 short int var4 /* : Bool */;
 val* var5 /* : Array[Object] */;
 long var6 /* : Int */;
@@ -1211,8 +1215,10 @@ var = ((long (*)(val*))(self->class->vft[COLOR_toolcontext__ToolContext__verbose
 /* <var:Int> isa OTHER */
 var3 = 1; /* easy <var:Int> isa OTHER*/
 if (!var3) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Cast failed", "lib/standard/kernel.nit", 256);
-exit(1);
+var_class_name = type_kernel__Int.name;
+fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "OTHER", var_class_name);
+fprintf(stderr, " (%s:%d)\n", "lib/standard/kernel.nit", 264);
+show_backtrace(1);
 }
 var4 = var_level <= var;
 var1 = var4;
@@ -1226,7 +1232,6 @@ var6 = 1;
 var7 = NEW_array__NativeArray(var6, &type_array__NativeArraykernel__Object);
 ((struct instance_array__NativeArray*)var7)->values[0] = (val*) var_s;
 ((void (*)(val*, val*, long))(var5->class->vft[COLOR_array__Array__with_native]))(var5, var7, var6) /* with_native on <var5:Array[Object]>*/;
-CHECK_NEW_array__Array(var5);
 }
 var8 = ((val* (*)(val*))(var5->class->vft[COLOR_string__Object__to_s]))(var5) /* to_s on <var5:Array[Object]>*/;
 ((void (*)(val*, val*))(self->class->vft[COLOR_file__Object__print]))(self, var8) /* print on <self:ToolContext>*/;
@@ -1245,8 +1250,9 @@ val* var /* : OptionContext */;
 val* var1 /* : OptionContext */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64doption_context].val; /* @option_context on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @option_context", "src/toolcontext.nit", 136);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @option_context");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 136);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1277,8 +1283,9 @@ val* var /* : OptionCount */;
 val* var1 /* : OptionCount */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_warn].val; /* @opt_warn on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_warn", "src/toolcontext.nit", 139);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_warn");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 139);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1309,8 +1316,9 @@ val* var /* : OptionBool */;
 val* var1 /* : OptionBool */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_quiet].val; /* @opt_quiet on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_quiet", "src/toolcontext.nit", 142);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_quiet");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 142);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1341,8 +1349,9 @@ val* var /* : OptionBool */;
 val* var1 /* : OptionBool */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_log].val; /* @opt_log on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_log", "src/toolcontext.nit", 145);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_log");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 145);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1373,8 +1382,9 @@ val* var /* : OptionString */;
 val* var1 /* : OptionString */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_log_dir].val; /* @opt_log_dir on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_log_dir", "src/toolcontext.nit", 148);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_log_dir");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 148);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1405,8 +1415,9 @@ val* var /* : OptionBool */;
 val* var1 /* : OptionBool */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_help].val; /* @opt_help on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_help", "src/toolcontext.nit", 151);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_help");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 151);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1437,8 +1448,9 @@ val* var /* : OptionBool */;
 val* var1 /* : OptionBool */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_version].val; /* @opt_version on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_version", "src/toolcontext.nit", 154);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_version");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 154);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1469,8 +1481,9 @@ val* var /* : OptionCount */;
 val* var1 /* : OptionCount */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_verbose].val; /* @opt_verbose on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_verbose", "src/toolcontext.nit", 157);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_verbose");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 157);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1501,8 +1514,9 @@ val* var /* : OptionBool */;
 val* var1 /* : OptionBool */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_stop_on_first_error].val; /* @opt_stop_on_first_error on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_stop_on_first_error", "src/toolcontext.nit", 160);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_stop_on_first_error");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 160);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1533,8 +1547,9 @@ val* var /* : OptionBool */;
 val* var1 /* : OptionBool */;
 var1 = self->attrs[COLOR_toolcontext__ToolContext___64dopt_no_color].val; /* @opt_no_color on <self:ToolContext> */
 if (var1 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Uninitialized attribute @opt_no_color", "src/toolcontext.nit", 163);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @opt_no_color");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 163);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1626,7 +1641,6 @@ var12 = NEW_array__NativeArray(var11, &type_array__NativeArrayopts__Option);
 ((struct instance_array__NativeArray*)var12)->values[7] = (val*) var8;
 ((struct instance_array__NativeArray*)var12)->values[8] = (val*) var9;
 ((void (*)(val*, val*, long))(var10->class->vft[COLOR_array__Array__with_native]))(var10, var12, var11) /* with_native on <var10:Array[Option]>*/;
-CHECK_NEW_array__Array(var10);
 }
 ((void (*)(val*, val*))(var->class->vft[COLOR_opts__OptionContext__add_option]))(var, var10) /* add_option on <var:OptionContext>*/;
 RET_LABEL:;
@@ -1695,8 +1709,9 @@ if (var17){
 var18 = ((val* (*)(val*))(self->class->vft[COLOR_toolcontext__ToolContext__opt_log_dir]))(self) /* opt_log_dir on <self:ToolContext>*/;
 var19 = ((val* (*)(val*))(var18->class->vft[COLOR_opts__Option__value]))(var18) /* value on <var18:OptionString>*/;
 if (var19 == NULL) {
-fprintf(stderr, "Runtime error: %s (%s:%d)\n", "Cast failed", "src/toolcontext.nit", 187);
-exit(1);
+fprintf(stderr, "Runtime error: %s", "Cast failed");
+fprintf(stderr, " (%s:%d)\n", "src/toolcontext.nit", 187);
+show_backtrace(1);
 }
 ((void (*)(val*, val*))(self->class->vft[COLOR_toolcontext__ToolContext__log_directory_61d]))(self, var19) /* log_directory= on <self:ToolContext>*/;
 } else {