loc2uid exception can be caused by user configuration issue

[jurgenvinju]

In the following case I had compiled once with a --lib option and once after that without the --lib option:

getLoc2uid |file:///export/scratch1/jenkins/home/workspace/usethesource_rascal_master-S5ZKBVP7G6AAXOCX5AHV2IJ2QL35PDF5FJHTCPD6ZB5NPZDM4Q3Q/src/org/rascalmpl/library/util/Webserver.rsc|(711,93,<22,0>,<22,93>)
error@/util/Webserver.rsc:1:0: Unexpected compiler exception EXCEPTION in translateFunctionDeclaration, compiling response: getLoc2uid: |file:///export/scratch1/jenkins/home/workspace/usethesource_rascal_master-S5ZKBVP7G6AAXOCX5AHV2IJ2QL35PDF5FJHTCPD6ZB5NPZDM4Q3Q/src/org/rascalmpl/library/util/Webserver.rsc|(711,93,<22,0>,<22,93>)

Perhaps a "symbol not found" error message, a link-time or compile-time error could be issues instead of the internal error.