diff --git a/example_errors/bad_assert.ucg b/example_errors/bad_assert.ucg
new file mode 100644
index 0000000..e69de29
diff --git a/example_errors/bad_import.ucg b/example_errors/bad_import.ucg
new file mode 100644
index 0000000..efca996
--- /dev/null
+++ b/example_errors/bad_import.ucg
@@ -0,0 +1 @@
+import
\ No newline at end of file
diff --git a/example_errors/bad_file.ucg b/example_errors/bad_let_test.ucg
similarity index 100%
rename from example_errors/bad_file.ucg
rename to example_errors/bad_let_test.ucg
diff --git a/example_errors/errors_test.ucg b/example_errors/errors_test.ucg
index 7742c73..4510eb7 100644
--- a/example_errors/errors_test.ucg
+++ b/example_errors/errors_test.ucg
@@ -2,12 +2,14 @@ assert |macro |;
 assert |{ foo = hello world}|;
 assert |{ foo = "hello world"|;
 assert |{ = }|;
-assert |let foo |;
-assert |let |;
-assert |import |;
-assert |import foo |;
-assert |out |;
-assert |out "|;
-assert |out json|;
 assert |"|;
-assert |=|;
\ No newline at end of file
+assert |=|;
+
+assert |let |;
+assert |let foo |;
+assert |let foo =|;
+//assert |import |;
+//assert |import foo |;
+//assert |out |;
+//assert |out "|;
+//assert |out json|;
diff --git a/integration_tests/comparisons_test.ucg b/integration_tests/comparisons_test.ucg
index e63f522..b8983af 100644
--- a/integration_tests/comparisons_test.ucg
+++ b/integration_tests/comparisons_test.ucg
@@ -16,15 +16,33 @@ let list = [1, 2, 3];
 let list2 = list;
 let list3 = [1, 2];
 
-assert |one == one|;
-assert |one == one|;
-assert |one >= one|;
-assert |two > one|;
-assert |two >= two|;
-assert |tpl1 == tpl2|;
-assert |tpl1 != tpl3|;
-assert |list == list2|;
-assert |list != list3|;
+assert |
+    one == one;
+|;
+assert |
+    one == one;
+|;
+assert |
+    one >= one;
+|;
+assert |
+    two > one;
+|;
+assert |
+    two >= two;
+|;
+assert |
+    tpl1 == tpl2;
+|;
+assert |
+    tpl1 != tpl3;
+|;
+assert |
+    list == list2;
+|;
+assert |
+    list != list3;
+|;
 
 // Deep Comparisons
 let tpl4 = {
@@ -40,17 +58,33 @@ let less = {
     foo = "bar"
 };
 
-assert |tpl4.inner == copy.inner|;
-assert |tpl4.inner.fld == copy.inner.fld|;
-assert |tpl4.lst == copy.lst|;
-assert |tpl4.foo == copy.foo|;
-assert |tpl4 == copy|;
-assert |tpl4 != extra|;
-assert |tpl4 != less|;
+assert |
+    tpl4.inner == copy.inner;
+|;
+assert |
+    tpl4.inner.fld == copy.inner.fld;
+|;
+assert |
+    tpl4.lst == copy.lst;
+|;
+assert |
+    tpl4.foo == copy.foo;
+|;
+assert |
+    tpl4 == copy;
+|;
+assert |
+    tpl4 != extra;
+|;
+assert |
+    tpl4 != less;
+|;
 
 // Expression comparisons
-assert |2 == 1+1|;
-assert |(1+1) == 2|;
-assert |(1+1) == (1+1)|;
+assert |2 == 1+1;|;
+assert |(1+1) == 2;|;
+assert |(1+1) == (1+1);|;
 let want = "foo";
-assert |select want, 1, { foo=2, } == 2|;
\ No newline at end of file
+assert |
+    select want, 1, { foo=2, } == 2;
+|;
\ No newline at end of file
diff --git a/integration_tests/concatenation_test.ucg b/integration_tests/concatenation_test.ucg
index 2bbc58c..a7c6558 100644
--- a/integration_tests/concatenation_test.ucg
+++ b/integration_tests/concatenation_test.ucg
@@ -1,2 +1,6 @@
-assert |"hello " + "world" == "hello world"|;
-assert |[1, 2, 3] + [4, 5, 6] == [1, 2, 3, 4, 5, 6]|;
\ No newline at end of file
+assert |
+    "hello " + "world" == "hello world";
+|;
+assert |
+    [1, 2, 3] + [4, 5, 6] == [1, 2, 3, 4, 5, 6];
+|;
\ No newline at end of file
diff --git a/integration_tests/empty_test.ucg b/integration_tests/empty_test.ucg
index d6772ee..9707de3 100644
--- a/integration_tests/empty_test.ucg
+++ b/integration_tests/empty_test.ucg
@@ -2,4 +2,6 @@ let empty = NULL;
 let tpl = {
     foo = NULL,
 };
-assert |tpl.foo == empty|;
\ No newline at end of file
+assert |
+    tpl.foo == empty;
+|;
\ No newline at end of file
diff --git a/integration_tests/format_test.ucg b/integration_tests/format_test.ucg
index e2d825f..77016ca 100644
--- a/integration_tests/format_test.ucg
+++ b/integration_tests/format_test.ucg
@@ -1,4 +1,12 @@
-assert |"hello @" % ("world") == "hello world"|;
-assert |"1 @ @" % (2, 3) == "1 2 3"|;
-assert |"@ or @" % (true, false) == "true or false"|;
-assert |"@" % (NULL) == "NULL"|;
\ No newline at end of file
+assert |
+    "hello @" % ("world") == "hello world";
+|;
+assert |
+    "1 @ @" % (2, 3) == "1 2 3";
+|;
+assert |
+    "@ or @" % (true, false) == "true or false";
+|;
+assert |
+    "@" % (NULL) == "NULL";
+|;
\ No newline at end of file
diff --git a/integration_tests/list_ops_test.ucg b/integration_tests/list_ops_test.ucg
index 915effd..b27ca7a 100644
--- a/integration_tests/list_ops_test.ucg
+++ b/integration_tests/list_ops_test.ucg
@@ -12,11 +12,25 @@ let boolfiltrator = macro(item) => {
     result = item < 5,
 };
 
-assert |map mapper.result list1 == [2, 3, 4, 5]|;
-assert |(map mapper.result [1, 2, 3, 4]) == [2, 3, 4, 5]|;
-assert |map mapper.result [1, 2, 3, 4] == [2, 3, 4, 5]|;
+assert |
+map mapper.result list1 == [2, 3, 4, 5];
+|;
+assert |
+    (map mapper.result [1, 2, 3, 4]) == [2, 3, 4, 5];
+|;
+assert |
+    map mapper.result [1, 2, 3, 4] == [2, 3, 4, 5];
+|;
 
-assert |filter filtrator.result list2 == ["foo", "foo"]|;
-assert |(filter filtrator.result ["foo", "bar", "foo", "bar"]) == ["foo", "foo"]|;
-assert |filter filtrator.result ["foo", "bar", "foo", "bar"] == ["foo", "foo"]|;
-assert |filter boolfiltrator.result [1, 2, 3, 4, 5, 6, 7] == [1, 2, 3, 4]|;
\ No newline at end of file
+assert |
+    filter filtrator.result list2 == ["foo", "foo"];
+|;
+assert |
+    (filter filtrator.result ["foo", "bar", "foo", "bar"]) == ["foo", "foo"];
+|;
+assert |
+    filter filtrator.result ["foo", "bar", "foo", "bar"] == ["foo", "foo"];
+|;
+assert |
+    filter boolfiltrator.result [1, 2, 3, 4, 5, 6, 7] == [1, 2, 3, 4];
+|;
\ No newline at end of file
diff --git a/integration_tests/macros_test.ucg b/integration_tests/macros_test.ucg
index 0c63e04..d14dfc7 100644
--- a/integration_tests/macros_test.ucg
+++ b/integration_tests/macros_test.ucg
@@ -14,11 +14,25 @@ let cplxmacro = macro(argint, argstr, argfloat) => {
 let simpleresult = simplemacro(1, 2, 3);
 let cplxresult = cplxmacro(1, "We", 3.0);
 
-assert |simpleresult.field1 == 1|;
-assert |simpleresult.field2 == 2|;
-assert |simpleresult.field3 == 3|;
+assert |
+    simpleresult.field1 == 1;
+|;
+assert |
+    simpleresult.field2 == 2;
+|;
+assert |
+    simpleresult.field3 == 3;
+|;
 
-assert |cplxresult.field1 == 2|;
-assert |cplxresult.field2 == "We are here"|;
-assert |cplxresult.field3 == 2.0|;
-assert |cplxresult.boolfield == true|;
\ No newline at end of file
+assert |
+    cplxresult.field1 == 2;
+|;
+assert |
+    cplxresult.field2 == "We are here";
+|;
+assert |
+    cplxresult.field3 == 2.0;
+|;
+assert |
+    cplxresult.boolfield == true;
+|;
\ No newline at end of file
diff --git a/integration_tests/operator_precedence_test.ucg b/integration_tests/operator_precedence_test.ucg
index d66460b..2eabb9d 100644
--- a/integration_tests/operator_precedence_test.ucg
+++ b/integration_tests/operator_precedence_test.ucg
@@ -1,9 +1,27 @@
-assert |2 * 2 + 1 == 5|;
-assert |2 + 2 * 3 == 8|;
-assert |2 * (2 + 1) == 6|;
-assert |2 * 2 + 1 > 4|;
-assert |2 * 2 + 1 < 6|;
-assert |2 * 2 + 1 >= 5|;
-assert |2 * 2 + 1 <= 5|;
-assert |2 / 2  == 1|;
-assert |2 - 1 == 1|;
\ No newline at end of file
+assert |
+    2 * 2 + 1 == 5;
+|;
+assert |
+    2 + 2 * 3 == 8;
+|;
+assert |
+    2 * (2 + 1) == 6;
+|;
+assert |
+    2 * 2 + 1 > 4;
+|;
+assert |
+    2 * 2 + 1 < 6;
+|;
+assert |
+    2 * 2 + 1 >= 5;
+|;
+assert |
+    2 * 2 + 1 <= 5;
+|;
+assert |
+    2 / 2  == 1;
+|;
+assert |
+    2 - 1 == 1;
+|;
\ No newline at end of file
diff --git a/integration_tests/select_expressions_test.ucg b/integration_tests/select_expressions_test.ucg
index 0be2573..f49b9cd 100644
--- a/integration_tests/select_expressions_test.ucg
+++ b/integration_tests/select_expressions_test.ucg
@@ -11,8 +11,12 @@ let defaultgot = select badwant, "OOPS", {
     door2 = "you lose",
 };
 
-assert |got == "grand prize"|;
-assert |defaultgot == "OOPS"|;
+assert |
+    got == "grand prize";
+|;
+assert |
+    defaultgot == "OOPS";
+|;
 
 // select inside a macro
 
@@ -25,6 +29,12 @@ let condmacro = macro(arg) => {
 
 let result = condmacro("opt1");
 
-assert |condmacro("opt1") == {output = "yay"}|;
-assert |condmacro("opt2") == {output = "boo"}|;
-assert |condmacro("invalid") == {output = NULL}|;
\ No newline at end of file
+assert |
+    condmacro("opt1") == {output = "yay"};
+|;
+assert |
+    condmacro("opt2") == {output = "boo"};
+|;
+assert |
+    condmacro("invalid") == {output = NULL};
+|;
\ No newline at end of file
diff --git a/integration_tests/selectors_test.ucg b/integration_tests/selectors_test.ucg
index 207094d..745e83a 100644
--- a/integration_tests/selectors_test.ucg
+++ b/integration_tests/selectors_test.ucg
@@ -10,10 +10,24 @@ let testmacro = macro(arg) => {
     output = arg,
 };
 
-assert |list.0 == 1|;
-assert |list.1 == 2|;
-assert |list.3 == 4|;
-assert |tuple.field1 == 1|;
-assert |tuple.field2 == 3|;
-assert |tuple.deeplist.0 == "foo"|;
-assert |tuple.deeplist.1 == "bar"|;
\ No newline at end of file
+assert |
+    list.0 == 1;
+|;
+assert |
+    list.1 == 2;
+|;
+assert |
+    list.3 == 4;
+|;
+assert |
+    tuple.field1 == 1;
+|;
+assert |
+    tuple.field2 == 3;
+|;
+assert |
+    tuple.deeplist.0 == "foo";
+|;
+assert |
+    tuple.deeplist.1 == "bar";
+|;
\ No newline at end of file
diff --git a/integration_tests/tuple_test.ucg b/integration_tests/tuple_test.ucg
index 5b14114..82b00c5 100644
--- a/integration_tests/tuple_test.ucg
+++ b/integration_tests/tuple_test.ucg
@@ -14,11 +14,27 @@ let nestedtpl = {
     list = [1, 2, 3, 4],
 };
 
-assert |simpletpl.foo == "bar"|;
-assert |stringfieldtpl."field 1" == 1|;
-assert |nestedtpl.scalar == 1|;
-assert |nestedtpl.inner.field == "value"|;
-assert |nestedtpl.list.0 == 1|;
-assert |nestedtpl.list.1 == 2|;
-assert |nestedtpl.list.2 == 3|;
-assert |nestedtpl.list.3 == 4|;
\ No newline at end of file
+assert |
+    simpletpl.foo == "bar";
+|;
+assert |
+    stringfieldtpl."field 1" == 1;
+|;
+assert |
+    nestedtpl.scalar == 1;
+|;
+assert |
+    nestedtpl.inner.field == "value";
+|;
+assert |
+    nestedtpl.list.0 == 1;
+|;
+assert |
+    nestedtpl.list.1 == 2;
+|;
+assert |
+    nestedtpl.list.2 == 3;
+|;
+assert |
+    nestedtpl.list.3 == 4;
+|;
\ No newline at end of file
diff --git a/src/build/mod.rs b/src/build/mod.rs
index 19d54eb..f2303f2 100644
--- a/src/build/mod.rs
+++ b/src/build/mod.rs
@@ -25,6 +25,8 @@ use std::path::PathBuf;
 use std::rc::Rc;
 use std::string::ToString;
 
+use simple_error;
+
 use ast::*;
 use error;
 use format;
@@ -248,7 +250,7 @@ impl<'a> Builder<'a> {
         Ok(())
     }
 
-    fn eval_span(&mut self, input: OffsetStrIter) -> Result<Rc<Val>, Box<Error>> {
+    fn eval_input(&mut self, input: OffsetStrIter) -> Result<Rc<Val>, Box<Error>> {
         match parse(input.clone()) {
             Ok(stmts) => {
                 //panic!("Successfully parsed {}", input);
@@ -271,7 +273,7 @@ impl<'a> Builder<'a> {
 
     /// Evaluate an input string as UCG.
     pub fn eval_string(&mut self, input: &str) -> Result<Rc<Val>, Box<Error>> {
-        self.eval_span(OffsetStrIter::new(input))
+        self.eval_input(OffsetStrIter::new(input))
     }
 
     /// Builds a ucg file at the named path.
@@ -280,8 +282,19 @@ impl<'a> Builder<'a> {
         let mut f = try!(File::open(name));
         let mut s = String::new();
         try!(f.read_to_string(&mut s));
-        self.last = Some(try!(self.eval_string(&s)));
-        Ok(())
+        let eval_result = self.eval_string(&s);
+        match eval_result {
+            Ok(v) => {
+                self.last = Some(v);
+                Ok(())
+            }
+            Err(e) => {
+                let err = simple_error::SimpleError::new(
+                    format!("Error building file: {}\n{}", name, e.as_ref()).as_ref(),
+                );
+                Err(Box::new(err))
+            }
+        }
     }
 
     fn build_import(&mut self, def: &ImportDef) -> Result<Rc<Val>, Box<Error>> {
@@ -993,13 +1006,10 @@ impl<'a> Builder<'a> {
             // we are not in validate_mode then build_asserts are noops.
             return Ok(Rc::new(Val::Empty));
         }
-        let mut expr_as_stmt = String::new();
         let expr = &tok.fragment;
-        expr_as_stmt.push_str(expr);
-        expr_as_stmt.push_str(";");
         let assert_input =
-            OffsetStrIter::new_with_offsets(&expr_as_stmt, tok.pos.line - 1, tok.pos.column - 1);
-        let ok = match self.eval_span(assert_input) {
+            OffsetStrIter::new_with_offsets(expr, tok.pos.line - 1, tok.pos.column - 1);
+        let ok = match self.eval_input(assert_input) {
             Ok(v) => v,
             Err(e) => {
                 // failure!
diff --git a/src/lib.rs b/src/lib.rs
index 7b85b23..a43f562 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -409,15 +409,19 @@
 //!
 //! The assert statement defines an expression that must evaluate to either true or false. Assert statements are noops except
 //! during a validation compile. They give you a way to assert certains properties about your data and can be used as a form
-//! of unit testing for your configurations. It starts with the assert keyword followed by a valid boolean ucg expression
-//! delimited by `|` characters.
+//! of unit testing for your configurations. It starts with the assert keyword followed by a valid block of ucg statements
+//! delimited by `|` characters. The final statement in the in the block must evaluate to a boolean expression.
 //!
 //! ```ucg
-//! assert host == "www.example.com";
-//! assert |select qa, 443, {
-//!   qa = 80,
-//!   prod = 443,
-//! } == 443|;
+//! assert |
+//!     host == "www.example.com";
+//! |;
+//! assert |
+//!     select qa, 443, {
+//!       qa = 80,
+//!       prod = 443,
+//!     } == 443;
+//! |;
 //! ```
 //!
 //! When _test.ucg files are run in a validation run then ucg will output a log of all the assertions
diff --git a/src/parse/mod.rs b/src/parse/mod.rs
index a65bf13..fc0c000 100644
--- a/src/parse/mod.rs
+++ b/src/parse/mod.rs
@@ -843,9 +843,10 @@ fn tuple_to_let(tok: Token, expr: Expression) -> Statement {
 make_fn!(
     let_stmt_body<SliceIter<Token>, Statement>,
     do_each!(
-        name => match_type!(BAREWORD),
+        name => wrap_err!(match_type!(BAREWORD), "Expected name for binding"),
         _ => punct!("="),
-        val => trace_nom!(expression),
+        // TODO(jwall): Wrap this error with an appropriate abortable_parser::Error
+        val => wrap_err!(trace_nom!(expression), "Expected Expression"),
         _ => punct!(";"),
         (tuple_to_let(name, val))
     )
@@ -870,9 +871,9 @@ fn tuple_to_import(tok: Token, tok2: Token) -> Statement {
 make_fn!(
     import_stmt_body<SliceIter<Token>, Statement>,
     do_each!(
-        path => match_type!(STR),
+        path => wrap_err!(match_type!(STR), "Expected import path"),
         _ => word!("as"),
-        name => match_type!(BAREWORD),
+        name => wrap_err!(match_type!(BAREWORD), "Expected import name"),
         _ => punct!(";"),
         (tuple_to_import(path, name))
     )
@@ -902,8 +903,8 @@ make_fn!(
     out_statement<SliceIter<Token>, Statement>,
     do_each!(
         _ => word!("out"),
-        typ => must!(match_type!(BAREWORD)),
-        expr => must!(expression),
+        typ => wrap_err!(must!(match_type!(BAREWORD)), "Expected converter name"),
+        expr => wrap_err!(must!(expression), "Expected Expression to export"),
         _ => must!(punct!(";")),
         (Statement::Output(typ.clone(), expr.clone()))
     )