From b32b4181604164d9419f5fe388d70314e1bc6896 Mon Sep 17 00:00:00 2001
From: Matthias Dittrich <matthi.d@googlemail.com>
Date: Mon, 19 Jan 2015 14:01:35 +0100
Subject: [PATCH] ignore unknown project references.

---
 src/app/FakeLib/MSBuildHelper.fs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/app/FakeLib/MSBuildHelper.fs b/src/app/FakeLib/MSBuildHelper.fs
index ea441d4be3f..48bd9884253 100644
--- a/src/app/FakeLib/MSBuildHelper.fs
+++ b/src/app/FakeLib/MSBuildHelper.fs
@@ -82,7 +82,7 @@ let rec getProjectReferences (projectFileName : string) =
     else // exclude .sln-files since the are not XML
          
     let doc = loadProject projectFileName
-    let references = getReferenceElements "ProjectReference" projectFileName doc |> Seq.map snd
+    let references = getReferenceElements "ProjectReference" projectFileName doc |> Seq.map snd |> Seq.filter File.Exists
     references
       |> Seq.map getProjectReferences
       |> Seq.concat