Klever

Now BenchExec is used in such a way that we can not support:

1. collecting multiple error traces from verifiers
2. support arbitrary verifiers from SV-COMP

The problems found in both local and vcloud scheduler clients and needs refactoring of VTG strategies.

• For collecting error traces the local client should use paths provided by verifier to find the resulting witnesses. Right now the corresponding code is hardcoded into both VTG strategy and local client especially for CPAchecker.
• The vcloud client uses home made functions for processing results, it should use a library functions provided for that purpose. It will enable support for all features of BenchExec including correct path for collecting results and proper determination of verdicts.