diff --git a/lib/std/core/builtin.c3 b/lib/std/core/builtin.c3
index 73d0617fc..c8ad66ad3 100644
--- a/lib/std/core/builtin.c3
+++ b/lib/std/core/builtin.c3
@@ -104,13 +104,29 @@ fn void default_panic(String message, String file, String function, uint line) @
 	$$trap();
 
 }
+
+macro void abort(String string = "Unrecoverable error reached", ...) @builtin @noreturn
+{
+	panicf(string, $$FILE, $$FUNC, $$LINE, $vasplat);
+	$$trap();
+}
+
+bool in_panic @local = false;
+
 fn void default_panic(String message, String file, String function, uint line) @if(!env::NATIVE_STACKTRACE)
 {
+	if (in_panic)
+	{
+		io::eprintn("Panic inside of panic.");
+		return;
+	}
+	in_panic = true;
 	$if $defined(io::stderr):
 	io::eprint("\nERROR: '");
 	io::eprint(message);
 	io::eprintfn("', in %s (%s:%d)", function, file, line);
 	$endif
+	in_panic = false;
 	$$trap();
 }
 
@@ -120,11 +136,19 @@ PanicFn panic = &default_panic;
 
 fn void panicf(String fmt, String file, String function, uint line, args...)
 {
+	if (in_panic)
+	{
+		io::eprint("Panic inside of panic: ");
+		io::eprintn(fmt);
+		return;
+	}
+	in_panic = true;
 	@stack_mem(512; Allocator allocator)
 	{
 		DString s;
 		s.new_init(.allocator = allocator);
 		s.appendf(fmt, ...args);
+		in_panic = false;
 		panic(s.str_view(), file, function, line);
 	};
 }
diff --git a/lib/std/io/formatter.c3 b/lib/std/io/formatter.c3
index 857c34bf2..4b455e4bb 100644
--- a/lib/std/io/formatter.c3
+++ b/lib/std/io/formatter.c3
@@ -15,24 +15,14 @@ fault PrintFault
 {
 	BUFFER_EXCEEDED,
 	INTERNAL_BUFFER_EXCEEDED,
-	INVALID_FORMAT_STRING,
-	MISSING_ARG,
-	INVALID_ARGUMENT_TYPE,
-}
-
-fault FormattingFault
-{
-	UNTERMINATED_FORMAT,
-	MISSING_ARG,
-	INVALID_WIDTH_ARG,
-	INVALID_FORMAT_TYPE,
+	INVALID_FORMAT,
+	NOT_ENOUGH_ARGUMENTS,
+	INVALID_ARGUMENT,
 }
 
 def OutputFn = fn void!(void* buffer, char c);
 def FloatType = double;
 
-
-
 fn usz! Formatter.printf(&self, String format, args...)
 {
 	return self.vprintf(format, args) @inline;
@@ -48,6 +38,7 @@ struct Formatter
 		uint width;
 		uint prec;
 		usz idx;
+		anyfault first_fault;
 	}
 }
 
@@ -69,7 +60,12 @@ fn void Formatter.init(&self, OutputFn out_fn, void* data = null)
 
 fn usz! Formatter.out(&self, char c) @private
 {
-	self.out_fn(self.data, c)!;
+	if (catch err = self.out_fn(self.data, c))
+	{
+		if (self.first_fault) return self.first_fault?;
+		self.first_fault = err;
+		return err?;
+	}
 	return 1;
 }
 
@@ -136,7 +132,7 @@ fn usz! Formatter.out_str(&self, any arg) @private
 			}
 			self.flags = {};
 			self.width = 0;
-			return self.ntoa_any(arg, 10);
+			return self.ntoa_any(arg, 10) ?? self.out_substr("<INVALID>");
 		case FLOAT:
 			PrintFlags flags = self.flags;
 			uint width = self.width;
@@ -147,7 +143,7 @@ fn usz! Formatter.out_str(&self, any arg) @private
 			}
 			self.flags = {};
 			self.width = 0;
-			return self.ftoa(float_from_any(arg)!!);
+			return self.ftoa(float_from_any(arg)) ?? self.out_substr("ERR");
 		case BOOL:
 			return self.out_substr(*(bool*)arg.ptr ? "true" : "false");
 		default:
@@ -292,10 +288,31 @@ fn void! out_null_fn(void* data @unused, char c @unused) @private
 {
 }
 
+macro usz! @report_fault(Formatter* f, $fault)
+{
+	(void)f.out_substr($fault);
+	return PrintFault.INVALID_FORMAT?;
+}
 
+macro usz! @wrap_bad(Formatter* f, #action)
+{
+	usz! len = #action;
+	if (catch err = len)
+	{
+		case PrintFault.BUFFER_EXCEEDED:
+        case PrintFault.INTERNAL_BUFFER_EXCEEDED:
+            return f.first_err(err)?;
+        default:
+            err = f.first_err(PrintFault.INVALID_ARGUMENT);
+            f.out_substr("<INVALID>")!;
+            return err?;
+	}
+	return len;
+}
 
 fn usz! Formatter.vprintf(&self, String format, any[] anys)
 {
+	self.first_fault = {};
 	if (!self.out_fn)
 	{
 		// use null output function
@@ -315,7 +332,7 @@ fn usz! Formatter.vprintf(&self, String format, any[] anys)
 			continue;
 		}
 		i++;
-		if (i >= format_len) return PrintFault.INVALID_FORMAT_STRING?;
+		if (i >= format_len) return @report_fault(self, "%ERR");
 		c = format[i];
 		if (c == '%')
 		{
@@ -335,11 +352,12 @@ fn usz! Formatter.vprintf(&self, String format, any[] anys)
 				case '#': self.flags.hash = true;
 				default: break FLAG_EVAL;
 			}
-			if (++i >= format_len) return PrintFault.INVALID_FORMAT_STRING?;
+			if (++i >= format_len) return @report_fault(self, "%ERR");
 			c = format[i];
 		}
 		// evaluate width field
-		int w = printf_parse_format_field(anys.ptr, anys.len, &variant_index, format.ptr, format.len, &i)!;
+		int! w = printf_parse_format_field(anys.ptr, anys.len, &variant_index, format.ptr, format.len, &i);
+		if (catch w) return @report_fault(self, "%ERR");
 		c = format[i];
 		if (w < 0)
 		{
@@ -352,15 +370,21 @@ fn usz! Formatter.vprintf(&self, String format, any[] anys)
 		if (c == '.')
 		{
 			self.flags.precision = true;
-			if (++i >= format_len) return PrintFault.INVALID_FORMAT_STRING?;
-			int prec = printf_parse_format_field(anys.ptr, anys.len, &variant_index, format.ptr, format.len, &i)!;
+			if (++i >= format_len) return @report_fault(self, "<BAD FORMAT>");
+			int! prec = printf_parse_format_field(anys.ptr, anys.len, &variant_index, format.ptr, format.len, &i);
+			if (catch prec) return @report_fault(self, "<BAD FORMAT>");
 			self.prec = prec < 0 ? 0 : prec;
 			c = format[i];
 		}
 
 		// evaluate specifier
 		uint base = 0;
-		if (variant_index >= anys.len) return PrintFault.MISSING_ARG?;
+		if (variant_index >= anys.len)
+		{
+			self.first_err(PrintFault.NOT_ENOUGH_ARGUMENTS);
+			total_len += self.out_substr("<MISSING>")!;
+			continue;
+		}
 		any current = anys[variant_index++];
 		switch (c)
 		{
@@ -386,25 +410,25 @@ fn usz! Formatter.vprintf(&self, String format, any[] anys)
 				self.flags.uppercase = true;
 				nextcase;
 			case 'a':
-				total_len += self.atoa(float_from_any(current)!!)!;
+				total_len += @wrap_bad(self, self.atoa(float_from_any(current)))!;
 				continue;
 			case 'F' :
 				self.flags.uppercase = true;
 				nextcase;
 			case 'f':
-				total_len += self.ftoa(float_from_any(current)!!)!;
+				total_len += @wrap_bad(self, self.ftoa(float_from_any(current)))!;
 				continue;
 			case 'E':
 				self.flags.uppercase = true;
 				nextcase;
 			case 'e':
-				total_len += self.etoa(float_from_any(current)!!)!;
+				total_len += @wrap_bad(self, self.etoa(float_from_any(current)))!;
 				continue;
 			case 'G':
 				self.flags.uppercase = true;
 				nextcase;
 			case 'g':
-				total_len += self.gtoa(float_from_any(current)!!)!;
+				total_len += @wrap_bad(self, self.gtoa(float_from_any(current)))!;
 				continue;
 			case 'c':
 				total_len += self.out_char(current)!;
@@ -429,7 +453,9 @@ fn usz! Formatter.vprintf(&self, String format, any[] anys)
 				self.flags.hash = true;
 				base = 16;
 			default:
-				return PrintFault.INVALID_FORMAT_STRING?;
+				self.first_err(PrintFault.INVALID_FORMAT);
+				total_len += self.out_substr("<BAD FORMAT>")!;
+				continue;
 		}
 		if (base != 10)
 		{
@@ -440,14 +466,13 @@ fn usz! Formatter.vprintf(&self, String format, any[] anys)
 		if (self.flags.precision) self.flags.zeropad = false;
 
 		bool is_neg;
-		uint128 v = int_from_any(current, &is_neg)!!;
-
-		total_len += self.ntoa(v, is_neg, base)!;
+		total_len += @wrap_bad(self, self.ntoa(int_from_any(current, &is_neg), is_neg, base))!;
 	}
 	// termination
 	//	out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen);
 
 	// return written chars without terminating \0
+	if (self.first_fault) return self.first_fault?;
 	return total_len;
 }
 
diff --git a/lib/std/io/formatter_private.c3 b/lib/std/io/formatter_private.c3
index 793afe62a..ae3b8b3de 100644
--- a/lib/std/io/formatter_private.c3
+++ b/lib/std/io/formatter_private.c3
@@ -4,6 +4,18 @@ import std::math;
 const char[16] XDIGITS_H = "0123456789ABCDEF";
 const char[16] XDIGITS_L = "0123456789abcdef";
 
+fault FormattingFault
+{
+	BAD_FORMAT
+}
+
+macro Formatter.first_err(&self, anyfault f)
+{
+	if (self.first_fault) return self.first_fault;
+	self.first_fault = f;
+	return f;
+}
+
 fn usz! Formatter.adjust(&self, usz len) @local
 {
 	if (!self.flags.left) return 0;
@@ -21,6 +33,7 @@ fn uint128! int_from_any(any arg, bool *is_neg) @private
 		case TypeKind.ENUM:
 			return int_from_any(arg.as_inner(), is_neg);
 		default:
+			break;
 	}
 	*is_neg = false;
 	switch (arg)
@@ -59,7 +72,7 @@ fn uint128! int_from_any(any arg, bool *is_neg) @private
 			double d = *arg;
 			return (uint128)((*is_neg = d < 0) ? -d : d);
 		default:
-			return PrintFault.INVALID_ARGUMENT_TYPE?;
+			return FormattingFault.BAD_FORMAT?;
 	}
 }
 
@@ -101,7 +114,7 @@ fn FloatType! float_from_any(any arg) @private
 		case double:
 			return (FloatType)*arg;
 		default:
-			return PrintFault.INVALID_ARGUMENT_TYPE?;
+			return FormattingFault.BAD_FORMAT?;
 	}
 }
 
@@ -588,8 +601,7 @@ fn usz! Formatter.ntoa_format(&self, String buf, usz len, bool negative, uint ba
 fn usz! Formatter.ntoa_any(&self, any arg, uint base) @private
 {
 	bool is_neg;
-	uint128 val = int_from_any(arg, &is_neg)!!;
-	return self.ntoa(val, is_neg, base) @inline;
+	return self.ntoa(int_from_any(arg, &is_neg)!!, is_neg, base) @inline;
 }
 
 fn usz! Formatter.out_char(&self, any arg) @private
@@ -640,17 +652,6 @@ fn usz! Formatter.out_reverse(&self, char[] buf) @private
 	return n;
 }
 
-fn void! printf_advance_format(usz format_len, usz *index_ptr) @inline @private
-{
-	usz val = ++(*index_ptr);
-	if (val >= format_len) return FormattingFault.UNTERMINATED_FORMAT?;
-}
-
-fn any! next_any(any* args_ptr, usz args_len, usz* arg_index_ptr) @inline @private
-{
-	if (*arg_index_ptr >= args_len) return FormattingFault.MISSING_ARG?;
-	return args_ptr[(*arg_index_ptr)++];
-}
 
 fn int! printf_parse_format_field(
 	any* args_ptr, usz args_len, usz* args_index_ptr,
@@ -659,9 +660,11 @@ fn int! printf_parse_format_field(
 	char c = format_ptr[*index_ptr];
 	if (c.is_digit()) return simple_atoi(format_ptr, format_len, index_ptr);
 	if (c != '*') return 0;
-	printf_advance_format(format_len, index_ptr)!;
-	any val = next_any(args_ptr, args_len, args_index_ptr)!;
-	if (!val.type.kindof.is_int()) return FormattingFault.INVALID_WIDTH_ARG?;
+	usz len = ++(*index_ptr);
+    if (len >= format_len) return FormattingFault.BAD_FORMAT?;
+	if (*args_index_ptr >= args_len) return FormattingFault.BAD_FORMAT?;
+	any val = args_ptr[(*args_index_ptr)++];
+	if (!val.type.kindof.is_int()) return FormattingFault.BAD_FORMAT?;
 	uint! intval = types::any_to_int(val, int);
-	return intval ?? FormattingFault.INVALID_WIDTH_ARG?;
+	return intval ?? FormattingFault.BAD_FORMAT?;
 }
diff --git a/lib/std/io/io.c3 b/lib/std/io/io.c3
index 014af8c2c..17a920d8c 100644
--- a/lib/std/io/io.c3
+++ b/lib/std/io/io.c3
@@ -256,7 +256,7 @@ fn usz! printfn(String format, args...) @maydiscard
 {
 	Formatter formatter;
 	formatter.init(&out_putchar_fn);
-	usz len = formatter.vprintf(format, args)!;
+	usz! len = formatter.vprintf(format, args);
 	putchar('\n');
 	io::stdout().flush()!;
 	return len + 1;
@@ -290,10 +290,10 @@ fn usz! eprintfn(String format, args...) @maydiscard
 	Formatter formatter;
 	OutStream stream = stderr();
 	formatter.init(&out_putstream_fn, &stream);
-	usz len = formatter.vprintf(format, args)! + 1;
+	usz! len = formatter.vprintf(format, args);
 	stderr().write_byte('\n')!;
 	stderr().flush()!;
-	return len;
+	return len + 1;
 }
 
 /**
diff --git a/releasenotes.md b/releasenotes.md
index 8c56b7360..18d3ef850 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -97,6 +97,7 @@
 - Methods can now properly be aliased using `def` #1393.
 - Memory leak in Object when not using temp allocators.
 - Tracking allocator would double the allocations in the report.
+- `printf` will now show errors in the output when there are errors.
 
 ### Stdlib changes