Return message when converting EasyBuildError to string

This ensures any formatting like newlines is kept.

Author: Flamefire

easybuild/tools/build_log.py

@@ -139,7 +139,7 @@ def __init__(self, msg, *args, exit_code=EasyBuildExit.ERROR, **kwargs):
 
     def __str__(self):
         """Return string representation of this EasyBuildError instance."""
-        return repr(self.msg)
+        return self.msg
 
 
 def raise_easybuilderror(msg, *args):