1.1 --- a/src/Pure/System/build.scala	Tue Jul 24 20:56:18 2012 +0200
     1.2 +++ b/src/Pure/System/build.scala	Tue Jul 24 21:07:54 2012 +0200
     1.3 @@ -331,7 +331,12 @@
     1.4                  }
     1.5                thy :: uses
     1.6              }).flatten ::: info.files.map(file => info.dir + file)
     1.7 -          val sources = all_files.map(p => (p, SHA1.digest(p)))
     1.8 +          val sources =
     1.9 +            try { all_files.map(p => (p, SHA1.digest(p))) }
    1.10 +            catch {
    1.11 +              case ERROR(msg) =>
    1.12 +                error(msg + "\nThe error(s) above occurred in session " + quote(name))
    1.13 +            }
    1.14  
    1.15            deps + (name -> Node(loaded_theories, sources))
    1.16        }))