EHPDFHeadlessRenderError

EHPDFHeadlessRenderError = class(Exception);

Declared in HPDFHeadlessCairoDevice; reports invalid rendering options, exhausted budgets, cooperative cancellation, unsupported content, malformed render geometry, cyclic Forms and publication failures

The exception carries a diagnostic message without a stable enumerated error code; applications ought not to parse its message as a protocol

Borrowed document callbacks can also raise EHPDFHeadlessDocumentError, the runtime bridge may raise EHPDFCairoError, and a caller-owned destination can raise its own I/O exception

Budget, content and cancellation errors happen before stream publication; a final stream write failure may retain accepted bytes, whilst the file helper keeps staging private until atomic publication

Failures leave the borrowed source document unchanged; callers keep ownership of the document, token and output stream

See Native Linux Cairo renderer for scope and atomic file output for destination preservation