1 files changed, 3 insertions, 2 deletions
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index e4cbc660f..8df8055b3 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -17,6 +17,7 @@ MakeError(ThrownError, AssertionError);
 MakeError(Abort, EvalError);
 MakeError(TypeError, EvalError);
 MakeError(UndefinedVarError, Error);
+MakeError(MissingArgumentError, EvalError);
 MakeError(RestrictedPathError, Error);
 
 
@@ -129,7 +130,7 @@ struct ExprPath : Expr
 {
     string s;
     Value v;
-    ExprPath(const string & s) : s(s) { mkPathNoCopy(v, this->s.c_str()); };
+    ExprPath(const string & s) : s(s) { v.mkPath(this->s.c_str()); };
     COMMON_METHODS
     Value * maybeThunk(EvalState & state, Env & env);
 };
@@ -238,7 +239,7 @@ struct ExprLambda : Expr
     {
         if (!arg.empty() && formals && formals->argNames.find(arg) != formals->argNames.end())
             throw ParseError({
-                .hint = hintfmt("duplicate formal function argument '%1%'", arg),
+                .msg = hintfmt("duplicate formal function argument '%1%'", arg),
                 .errPos = pos
             });
     };