Exceptions

Hierarchy

Exception
└── LocustNotFoundException
└── LoadDensityTestException
    ├── LoadDensityTestJsonException
    ├── LoadDensityGenerateJsonReportException
    ├── LoadDensityTestExecuteException
    ├── LoadDensityAssertException
    ├── LoadDensityHTMLException
    ├── LoadDensityAddCommandException
    ├── XMLException
    │   └── XMLTypeException
    └── CallbackExecutorException

When to catch what

• LoadDensityTestExecuteException — Action JSON shape is wrong, or an unknown command was referenced. Catch this to surface user-input errors without crashing on internal exceptions.

• LoadDensityHTMLException / LoadDensityGenerateJsonReportException — Report generation ran with no records (in-memory store empty).

• LoadDensityAssertException — Reserved for future use by the assertions layer; HTTP assertions today fail the request via Locust rather than raise.

• XMLException / XMLTypeException — Malformed XML or unexpected payload shape in the XML utilities.

• CallbackExecutorException — The callback executor was given an invalid trigger or function reference.

• LoadDensityAddCommandException — add_command_to_executor was passed a non-callable.

All custom exceptions inherit from LoadDensityTestException, so catching that one class is enough for blanket error handling.