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

diff --git a/c_src/poset.sep.1.c b/c_src/poset.sep.1.c
index a4ae105..ec3f4d8 100644
--- a/c_src/poset.sep.1.c
+++ b/c_src/poset.sep.1.c
@@ -30,7 +30,7 @@ var1 = self->attrs[COLOR_poset__POSet___64delements].val; /* @elements on <self:
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @elements");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 31);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -66,7 +66,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "HashMap[POSet#0, POSetElement[POSet#0]]", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 31);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSet___64delements].val = p0; /* @elements on <self:POSet[Object]> */
 RET_LABEL:;
@@ -102,7 +102,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "Collection#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 34);
-exit(1);
+show_backtrace(1);
 }
 var_e = p0;
 var2 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSet__elements]))(self) /* elements on <self:POSet[Object]>*/;
@@ -157,7 +157,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 36);
-exit(1);
+show_backtrace(1);
 }
 var_e = p0;
 var2 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSet__elements]))(self) /* elements on <self:POSet[Object]>*/;
@@ -174,7 +174,6 @@ var7 = NEW_poset__POSetElement(self->type->resolution_table->types[COLOR_poset__
 var8 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSet__elements]))(self) /* elements on <self:POSet[Object]>*/;
 var9 = ((long (*)(val*))(var8->class->vft[COLOR_abstract_collection__MapRead__length]))(var8) /* length on <var8:HashMap[Object, POSetElement[Object]]>*/;
 ((void (*)(val*, val*, val*, long))(var7->class->vft[COLOR_poset__POSetElement__init]))(var7, self, var_e, var9) /* init on <var7:POSetElement[Object]>*/;
-CHECK_NEW_poset__POSetElement(var7);
 var_poe = var7;
 var10 = ((val* (*)(val*))(var_poe->class->vft[COLOR_poset__POSetElement__tos]))(var_poe) /* tos on <var_poe:POSetElement[Object]>*/;
 ((void (*)(val*, val*))(var10->class->vft[COLOR_abstract_collection__SimpleCollection__add]))(var10, var_e) /* add on <var10:HashSet[Object]>*/;
@@ -224,7 +223,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 50);
-exit(1);
+show_backtrace(1);
 }
 var_e = p0;
 var2 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSet__elements]))(self) /* elements on <self:POSet[Object]>*/;
@@ -233,7 +232,7 @@ var4 = ((short int (*)(val*, val*))(var3->class->vft[COLOR_abstract_collection__
 if (!var4) {
 fprintf(stderr, "Runtime error: %s", "Assert failed");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 63);
-exit(1);
+show_backtrace(1);
 }
 var5 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSet__elements]))(self) /* elements on <self:POSet[Object]>*/;
 var6 = ((val* (*)(val*, val*))(var5->class->vft[COLOR_abstract_collection__MapRead___91d_93d]))(var5, var_e) /* [] on <var5:HashMap[Object, POSetElement[Object]]>*/;
@@ -333,7 +332,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 67);
-exit(1);
+show_backtrace(1);
 }
 /* Covariant cast for argument 1 (t) <p1:Object> isa POSet#0 */
 /* <p1:Object> isa POSet#0 */
@@ -349,7 +348,7 @@ if (!var1) {
 var_class_name5 = p1 == NULL ? "null" : p1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name5);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 67);
-exit(1);
+show_backtrace(1);
 }
 var_f = p0;
 var_t = p1;
@@ -499,7 +498,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 109);
-exit(1);
+show_backtrace(1);
 }
 /* Covariant cast for argument 1 (t) <p1:Object> isa POSet#0 */
 /* <p1:Object> isa POSet#0 */
@@ -515,7 +514,7 @@ if (!var2) {
 var_class_name6 = p1 == NULL ? "null" : p1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name6);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 109);
-exit(1);
+show_backtrace(1);
 }
 var_f = p0;
 var_t = p1;
@@ -587,7 +586,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 118);
-exit(1);
+show_backtrace(1);
 }
 /* Covariant cast for argument 1 (t) <p1:Object> isa POSet#0 */
 /* <p1:Object> isa POSet#0 */
@@ -603,7 +602,7 @@ if (!var2) {
 var_class_name6 = p1 == NULL ? "null" : p1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name6);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 118);
-exit(1);
+show_backtrace(1);
 }
 var_f = p0;
 var_t = p1;
@@ -755,10 +754,8 @@ var11 = 1;
 var12 = NEW_array__NativeArray(var11, &type_array__NativeArraystring__String);
 ((struct instance_array__NativeArray*)var12)->values[0] = (val*) var6;
 ((void (*)(val*, val*, long))(var10->class->vft[COLOR_array__Array__with_native]))(var10, var12, var11) /* with_native on <var10:Array[String]>*/;
-CHECK_NEW_array__Array(var10);
 }
 ((void (*)(val*, val*, val*))(var->class->vft[COLOR_exec__OProcess__init]))(var, var1, var10) /* init on <var:OProcess>*/;
-CHECK_NEW_exec__OProcess(var);
 var_f = var;
 if (varonce13) {
 var14 = varonce13;
@@ -804,7 +801,6 @@ var35 = NEW_array__NativeArray(var34, &type_array__NativeArraykernel__Object);
 ((struct instance_array__NativeArray*)var35)->values[1] = (val*) var_x;
 ((struct instance_array__NativeArray*)var35)->values[2] = (val*) var29;
 ((void (*)(val*, val*, long))(var33->class->vft[COLOR_array__Array__with_native]))(var33, var35, var34) /* with_native on <var33:Array[Object]>*/;
-CHECK_NEW_array__Array(var33);
 }
 var36 = ((val* (*)(val*))(var33->class->vft[COLOR_string__Object__to_s]))(var33) /* to_s on <var33:Array[Object]>*/;
 ((void (*)(val*, val*))(var_f->class->vft[COLOR_stream__OStream__write]))(var_f, var36) /* write on <var_f:OProcess>*/;
@@ -857,7 +853,6 @@ var61 = NEW_array__NativeArray(var60, &type_array__NativeArraykernel__Object);
 ((struct instance_array__NativeArray*)var61)->values[3] = (val*) var_y;
 ((struct instance_array__NativeArray*)var61)->values[4] = (val*) var55;
 ((void (*)(val*, val*, long))(var59->class->vft[COLOR_array__Array__with_native]))(var59, var61, var60) /* with_native on <var59:Array[Object]>*/;
-CHECK_NEW_array__Array(var59);
 }
 var62 = ((val* (*)(val*))(var59->class->vft[COLOR_string__Object__to_s]))(var59) /* to_s on <var59:Array[Object]>*/;
 ((void (*)(val*, val*))(var_f->class->vft[COLOR_stream__OStream__write]))(var_f, var62) /* write on <var_f:OProcess>*/;
@@ -899,7 +894,6 @@ var80 = NEW_array__NativeArray(var79, &type_array__NativeArraykernel__Object);
 ((struct instance_array__NativeArray*)var80)->values[3] = (val*) var_y;
 ((struct instance_array__NativeArray*)var80)->values[4] = (val*) var74;
 ((void (*)(val*, val*, long))(var78->class->vft[COLOR_array__Array__with_native]))(var78, var80, var79) /* with_native on <var78:Array[Object]>*/;
-CHECK_NEW_array__Array(var78);
 }
 var81 = ((val* (*)(val*))(var78->class->vft[COLOR_string__Object__to_s]))(var78) /* to_s on <var78:Array[Object]>*/;
 ((void (*)(val*, val*))(var_f->class->vft[COLOR_stream__OStream__write]))(var_f, var81) /* write on <var_f:OProcess>*/;
@@ -981,7 +975,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 151);
-exit(1);
+show_backtrace(1);
 }
 /* Covariant cast for argument 1 (b) <p1:Object> isa POSet#0 */
 /* <p1:Object> isa POSet#0 */
@@ -997,7 +991,7 @@ if (!var2) {
 var_class_name6 = p1 == NULL ? "null" : p1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet#0", var_class_name6);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 151);
-exit(1);
+show_backtrace(1);
 }
 var_a = p0;
 var_b = p1;
@@ -1064,7 +1058,7 @@ var1 = self->attrs[COLOR_poset__POSetElement___64dposet].val; /* @poset on <self
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @poset");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 181);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1100,7 +1094,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet[POSetElement#0]", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 181);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSetElement___64dposet].val = p0; /* @poset on <self:POSetElement[Object]> */
 RET_LABEL:;
@@ -1118,7 +1112,7 @@ var1 = self->attrs[COLOR_poset__POSetElement___64delement].val; /* @element on <
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @element");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 184);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1154,7 +1148,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSetElement#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 184);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSetElement___64delement].val = p0; /* @element on <self:POSetElement[Object]> */
 RET_LABEL:;
@@ -1172,7 +1166,7 @@ var1 = self->attrs[COLOR_poset__POSetElement___64dtos].val; /* @tos on <self:POS
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @tos");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 187);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1208,7 +1202,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "HashSet[POSetElement#0]", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 187);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSetElement___64dtos].val = p0; /* @tos on <self:POSetElement[Object]> */
 RET_LABEL:;
@@ -1226,7 +1220,7 @@ var1 = self->attrs[COLOR_poset__POSetElement___64dfroms].val; /* @froms on <self
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @froms");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 188);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1262,7 +1256,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "HashSet[POSetElement#0]", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 188);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSetElement___64dfroms].val = p0; /* @froms on <self:POSetElement[Object]> */
 RET_LABEL:;
@@ -1280,7 +1274,7 @@ var1 = self->attrs[COLOR_poset__POSetElement___64ddtos].val; /* @dtos on <self:P
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @dtos");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 189);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1316,7 +1310,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "HashSet[POSetElement#0]", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 189);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSetElement___64ddtos].val = p0; /* @dtos on <self:POSetElement[Object]> */
 RET_LABEL:;
@@ -1334,7 +1328,7 @@ var1 = self->attrs[COLOR_poset__POSetElement___64ddfroms].val; /* @dfroms on <se
 if (var1 == NULL) {
 fprintf(stderr, "Runtime error: %s", "Uninitialized attribute @dfroms");
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 190);
-exit(1);
+show_backtrace(1);
 }
 var = var1;
 RET_LABEL:;
@@ -1370,7 +1364,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "HashSet[POSetElement#0]", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 190);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSetElement___64ddfroms].val = p0; /* @dfroms on <self:POSetElement[Object]> */
 RET_LABEL:;
@@ -1509,7 +1503,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSetElement#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 222);
-exit(1);
+show_backtrace(1);
 }
 var_t = p0;
 var2 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSetElement__tos]))(self) /* tos on <self:POSetElement[Object]>*/;
@@ -1557,7 +1551,7 @@ if (!var1) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSetElement#0", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 228);
-exit(1);
+show_backtrace(1);
 }
 var_t = p0;
 var3 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSetElement__element]))(self) /* element on <self:POSetElement[Object]>*/;
@@ -1584,6 +1578,131 @@ var = var1;
 RET_LABEL:;
 return var;
 }
+/* method poset#POSetElement#depth for (self: POSetElement[Object]): Int */
+long poset__POSetElement__depth(val* self) {
+long var /* : Int */;
+val* var1 /* : Collection[Object] */;
+short int var2 /* : Bool */;
+long var3 /* : Int */;
+long var4 /* : Int */;
+long var5 /* : Int */;
+long var7 /* : Int */;
+long var_min /* var min: Int */;
+val* var8 /* : Collection[Object] */;
+val* var9 /* : Iterator[nullable Object] */;
+short int var10 /* : Bool */;
+val* var11 /* : nullable Object */;
+val* var_p /* var p: Object */;
+val* var12 /* : POSet[Object] */;
+val* var13 /* : POSetElement[Object] */;
+long var14 /* : Int */;
+long var15 /* : Int */;
+long var16 /* : Int */;
+long var18 /* : Int */;
+long var_d /* var d: Int */;
+short int var19 /* : Bool */;
+long var20 /* : Int */;
+long var21 /* : Int */;
+long var23 /* : Int */;
+short int var24 /* : Bool */;
+short int var26 /* : Bool */;
+short int var_ /* var : Bool */;
+short int var27 /* : Bool */;
+short int var29 /* : Bool */;
+int cltype;
+int idtype;
+const char* var_class_name;
+short int var30 /* : Bool */;
+var1 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSetElement__direct_greaters]))(self) /* direct_greaters on <self:POSetElement[Object]>*/;
+var2 = ((short int (*)(val*))(var1->class->vft[COLOR_abstract_collection__Collection__is_empty]))(var1) /* is_empty on <var1:Collection[Object]>*/;
+if (var2){
+var3 = 0;
+var = var3;
+goto RET_LABEL;
+} else {
+}
+var4 = 1;
+{ /* Inline kernel#Int#unary - (var4) */
+var7 = -var4;
+var5 = var7;
+goto RET_LABEL6;
+RET_LABEL6:(void)0;
+}
+var_min = var5;
+var8 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSetElement__direct_greaters]))(self) /* direct_greaters on <self:POSetElement[Object]>*/;
+var9 = ((val* (*)(val*))(var8->class->vft[COLOR_abstract_collection__Collection__iterator]))(var8) /* iterator on <var8:Collection[Object]>*/;
+for(;;) {
+var10 = ((short int (*)(val*))(var9->class->vft[COLOR_abstract_collection__Iterator__is_ok]))(var9) /* is_ok on <var9:Iterator[nullable Object]>*/;
+if(!var10) break;
+var11 = ((val* (*)(val*))(var9->class->vft[COLOR_abstract_collection__Iterator__item]))(var9) /* item on <var9:Iterator[nullable Object]>*/;
+var_p = var11;
+var12 = ((val* (*)(val*))(self->class->vft[COLOR_poset__POSetElement__poset]))(self) /* poset on <self:POSetElement[Object]>*/;
+var13 = ((val* (*)(val*, val*))(var12->class->vft[COLOR_poset__POSet___91d_93d]))(var12, var_p) /* [] on <var12:POSet[Object]>*/;
+var14 = ((long (*)(val*))(var13->class->vft[COLOR_poset__POSetElement__depth]))(var13) /* depth on <var13:POSetElement[Object]>*/;
+var15 = 1;
+{ /* Inline kernel#Int#+ (var14,var15) */
+var18 = var14 + var15;
+var16 = var18;
+goto RET_LABEL17;
+RET_LABEL17:(void)0;
+}
+var_d = var16;
+var20 = 1;
+{ /* Inline kernel#Int#unary - (var20) */
+var23 = -var20;
+var21 = var23;
+goto RET_LABEL22;
+RET_LABEL22:(void)0;
+}
+{ /* Inline kernel#Int#== (var_min,var21) */
+var26 = var_min == var21;
+var24 = var26;
+goto RET_LABEL25;
+RET_LABEL25:(void)0;
+}
+var_ = var24;
+if (var24){
+var19 = var_;
+} else {
+{ /* Inline kernel#Int#< (var_d,var_min) */
+/* Covariant cast for argument 0 (i) <var_min:Int> isa OTHER */
+/* <var_min:Int> isa OTHER */
+var29 = 1; /* easy <var_min:Int> isa OTHER*/
+if (!var29) {
+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", 265);
+show_backtrace(1);
+}
+var30 = var_d < var_min;
+var27 = var30;
+goto RET_LABEL28;
+RET_LABEL28:(void)0;
+}
+var19 = var27;
+}
+if (var19){
+var_min = var_d;
+} else {
+}
+CONTINUE_label: (void)0;
+((void (*)(val*))(var9->class->vft[COLOR_abstract_collection__Iterator__next]))(var9) /* next on <var9:Iterator[nullable Object]>*/;
+}
+BREAK_label: (void)0;
+var = var_min;
+goto RET_LABEL;
+RET_LABEL:;
+return var;
+}
+/* method poset#POSetElement#depth for (self: Object): Int */
+long VIRTUAL_poset__POSetElement__depth(val* self) {
+long var /* : Int */;
+long var1 /* : Int */;
+var1 = poset__POSetElement__depth(self);
+var = var1;
+RET_LABEL:;
+return var;
+}
 /* method poset#POSetElement#init for (self: POSetElement[Object], POSet[Object], Object, Int) */
 void poset__POSetElement__init(val* self, val* p0, val* p1, long p2) {
 short int var /* : Bool */;
@@ -1610,7 +1729,7 @@ if (!var) {
 var_class_name = p0 == NULL ? "null" : p0->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSet[POSetElement#0]", var_class_name);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 168);
-exit(1);
+show_backtrace(1);
 }
 /* Covariant cast for argument 1 (element) <p1:Object> isa POSetElement#0 */
 /* <p1:Object> isa POSetElement#0 */
@@ -1626,7 +1745,7 @@ if (!var1) {
 var_class_name5 = p1 == NULL ? "null" : p1->type->name;
 fprintf(stderr, "Runtime error: Cast failed. Expected `%s`, got `%s`", "POSetElement#0", var_class_name5);
 fprintf(stderr, " (%s:%d)\n", "lib/poset.nit", 168);
-exit(1);
+show_backtrace(1);
 }
 self->attrs[COLOR_poset__POSetElement___64dposet].val = p0; /* @poset on <self:POSetElement[Object]> */
 self->attrs[COLOR_poset__POSetElement___64delement].val = p1; /* @element on <self:POSetElement[Object]> */