diff --git a/include/tlibc/errors.h b/include/tlibc/errors.h
index 0c4918c..b9b5462 100755
--- a/include/tlibc/errors.h
+++ b/include/tlibc/errors.h
@@ -5,13 +5,13 @@
 
 typedef struct ErrorCallPos {
     i32 line;
-    str file; 
-    str func;
+    cstr file; 
+    cstr func;
 } ErrorCallPos;
 #define ErrorCallPos_here() (ErrorCallPos){\
     .line = __LINE__,\
-    .file = str_construct((char*)(void*)__FILE__, sizeof(__FILE__), true),\
-    .func = str_construct((char*)(void*)__func__, sizeof(__func__), true)\
+    .file = __FILE__,\
+    .func = __func__\
 }
 
 typedef struct Error {
@@ -21,7 +21,7 @@ typedef struct Error {
     List call_stack;
 } Error;
 
-Error* Error_create(const char* msg, bool is_msg_on_heap, ErrorCallPos);
+Error* Error_create(const char* msg, bool is_msg_on_heap, ErrorCallPos p);
 void Error_destroy(Error* e);
 void Error_addCallPos(Error* e, ErrorCallPos p);
 str Error_toStr(Error* e);
@@ -56,6 +56,7 @@ typedef struct Result_ {
 #define try_fatal(VAR, RSLT_CALL, DEFER_CODE) \
     Result_ VAR = RSLT_CALL;\
     if(VAR.error){\
+        Error_addCallPos(VAR.error, ErrorCallPos_here());\
         DEFER_CODE;\
         Error_printAndExit(VAR.error);\
     };
diff --git a/include/tlibc/string/StringBuilder.h b/include/tlibc/string/StringBuilder.h
index 726251d..77bf40e 100755
--- a/include/tlibc/string/StringBuilder.h
+++ b/include/tlibc/string/StringBuilder.h
@@ -16,7 +16,7 @@ void StringBuilder_destroy(StringBuilder* b);
 /// @param count set to -1 to clear StringBuilder
 void StringBuilder_removeFromEnd(StringBuilder* b, u32 count);
 void StringBuilder_append_char(StringBuilder* b, char c);
-void StringBuilder_append_cstr(StringBuilder* b, char* s);
+void StringBuilder_append_cstr(StringBuilder* b, cstr s);
 void StringBuilder_append_str(StringBuilder* b, str s);
 void StringBuilder_append_i64(StringBuilder* b, i64 a);
 void StringBuilder_append_u64(StringBuilder* b, u64 a);
diff --git a/src/errors.c b/src/errors.c
index 7611471..d9bffb2 100755
--- a/src/errors.c
+++ b/src/errors.c
@@ -3,11 +3,12 @@
 
 #define ERRMSG_LENGTH 1024
 
-Error* Error_create(const char* msg, bool is_msg_on_heap, ErrorCallPos){
+Error* Error_create(const char* msg, bool is_msg_on_heap, ErrorCallPos p){
     Error* e = (Error*)malloc(sizeof(Error));
     e->msg = str_construct((char*)(void*)msg, strlen(msg), true);
     e->is_msg_on_heap = is_msg_on_heap;
-    e->call_stack = List_alloc(ErrorCallPos, 1);
+    e->call_stack = List_alloc(ErrorCallPos, 16);
+    List_push(&e->call_stack, ErrorCallPos, p);
     return e;
 }
 
@@ -30,12 +31,12 @@ str Error_toStr(Error* e){
     for(u32 i = 0; i < len; i++){
         ErrorCallPos* ep = (ErrorCallPos*)e->call_stack.data + i;
         StringBuilder_append_str(&b, STR("\n  at "));
-        StringBuilder_append_str(&b, ep->file);
+        StringBuilder_append_cstr(&b, ep->file);
         StringBuilder_append_char(&b, ':');
         StringBuilder_append_i64(&b, ep->line);
         StringBuilder_append_char(&b, ' ');
-        StringBuilder_append_str(&b, ep->func);
-        StringBuilder_append_str(&b, STR("()\n"));
+        StringBuilder_append_cstr(&b, ep->func);
+        StringBuilder_append_str(&b, STR("()"));
     }
 
     return StringBuilder_getStr(&b);
@@ -43,7 +44,6 @@ str Error_toStr(Error* e){
 
 
 void Error_printAndExit(Error* e){
-    Error_addCallPos(e, ErrorCallPos_here());\
     str e_str = Error_toStr(e);
     printfe("%s\n", e_str.data);
     free(e_str.data);
diff --git a/src/string/StringBuilder.c b/src/string/StringBuilder.c
index 28a50e1..72f563a 100755
--- a/src/string/StringBuilder.c
+++ b/src/string/StringBuilder.c
@@ -33,8 +33,8 @@ void StringBuilder_append_str(StringBuilder* b, str s){
     List_push_size(&b->buffer, s.data, s.size);
 }
 
-void StringBuilder_append_cstr(StringBuilder* b, char* s){
-    StringBuilder_append_str(b, str_construct(s, strlen(s), true));
+void StringBuilder_append_cstr(StringBuilder* b, cstr s){
+    StringBuilder_append_str(b, str_construct((char*)(void*)s, strlen(s), true));
 }
 
 void StringBuilder_append_i64(StringBuilder* b, i64 n){
diff --git a/src/time.c b/src/time.c
index 16b04c2..369bbc7 100644
--- a/src/time.c
+++ b/src/time.c
@@ -17,14 +17,14 @@
 
 nsec_t getTimeNsec(){
     struct timespec t;
-    assert(clock_gettime(CLOCK_REALTIME, &t) != 0);
+    assert(clock_gettime(CLOCK_REALTIME, &t) == 0);
     u64 n = t.tv_sec * G + t.tv_nsec;
     return n;
 }
 
 usec_t getTimeUsec(){
     struct timespec t;
-    assert(clock_gettime(CLOCK_REALTIME, &t) != 0);
+    assert(clock_gettime(CLOCK_REALTIME, &t) == 0);
     u64 n = t.tv_sec * M + t.tv_nsec / K;
     return n;
 }
@@ -34,7 +34,7 @@ void sleepNsec(nsec_t time){
         .tv_sec = time / G,
         .tv_nsec = time % G
     };
-    assert(nanosleep(&t, NULL) != 0);
+    assert(nanosleep(&t, NULL) == 0);
 }
 
 void sleepUsec(usec_t time){