ErrLookup › deepset-ai/haystack

deepset-ai/haystack

Open-source AI orchestration framework for building context-engineered, production-ready LLM applications. Design modular pipelines and agent workflows with explicit control over retrieval, routing, memory, and generation. Built for scalable agents, RAG, multimodal applications, semantic search, and conversational systems. · Python · 316 source files

Analyzed at e318778c9b on 2026-08-30. 375 documented errors.

Code / MessageTypeSeverityTags
Failed to create JSON schema for the run method of Component
exception error pydantic, json-schema, tool-definition, component
Refusing to deserialize a ConditionalRouter with…
exception error deserialization, security, jinja, safe-mode
Could not import ' ' as it may not exist or is not a valid…
exception error python, deserialization, import-error, haystack
The provided break_point targets the same component and…
exception error pipeline, breakpoint, resume, snapshot
BreakpointException.from_triggered_breakpoint(break_point=br…
exception warning pipeline, breakpoint, control-flow
Could not apply arguments
exception error python, deserialization, generics, haystack
A `ChatMessage` must contain at least one `TextContent`…
validation error haystack, hugging-face, chatmessage, valueerror, empty-content
Warning: In an upcoming release, this method will require…
console warning deprecation, python, pipeline, keyword-arguments
Component ' ' of type ' ' has an unsupported value of type…
exception error serialization, python, haystack
Hook registered for hook point
validation error filesystem, skill-store, configuration, path
does not accept tools parameter in its run method. The…
validation error telemetry, pipeline, type-error, component
set_input_types()/set_input_type() cannot override the…
exception error haystack, component, input-types, sockets, componenterror
Refusing to deserialize
exception critical security, deserialization, haystack
Invalid hook point ' '. Valid hook points are: .
validation error yaml, skill-store, frontmatter, parsing
Failed to create JSON schema for function
exception error pydantic, json-schema, tool-definition
Failed to deserialize data
exception error python, pydantic, deserialization, haystack
Please provide an API key or an Azure Active Directory…
validation error authentication, azure, configuration, python
Found unclosed tag at position . Content: ' ...
validation error jinja2, chat-template, malformed-template
Input ' ' not found in component ' '.
validation error haystack, pipeline, validation, valueerror
'output_types' decorator can only be used on 'run' and…
exception error python, decorator, component, haystack
Cannot determine the value of the init parameter
exception error serialization, component, to-dict
Document with ID ' ' comes from the PDF file ' ' but is…
validation error python, haystack, image-converter, pdf, missing-metadata
Refusing to deserialize
exception critical security, deserialization, sandbox-escape
The Chat Generator returned no usable text to use as a…
exception error llm, empty-output, summary, runtime, compaction
Aggregate score missing for
validation error python, validation, evaluation
`compact_at` and `compact_to` must satisfy 0 < compact_to <…
validation error validation, constructor, config, compaction
OpenAIDocumentEmbedder expects a list of Documents as…
validation error python, type-error, embedders, openai
Pre-init hooks do not support components with variadic…
exception error haystack, component, init-signature, componenterror
Unknown extraction mode
validation error python, valueerror, enum, invalid-argument
tool_concurrency_limit must be greater than or equal to 1.
validation error security, path-traversal, skill-store, permission
{e}
exception error python, deserialization, import-error, haystack
PipelineRuntimeError.from_invalid_output(component_name…
exception error pipeline, component, type-error, return-type
Expected one ToolExecutionDecision for each tool call, but…
validation error python, validation, hooks, human-in-the-loop, tools
must be a sequence of numbers, got .
exception error type-error, validation, mock, embedding
Mutating attribute ' ' on an instance of ' ' can lead to…
console warning dataclass, immutability, python, pipeline
Cannot connect ' ' with ' ': their declared input and…
exception error pipeline, haystack, type-mismatch, connection
Component named not found in the pipeline.
exception error pipeline, haystack, missing-component, valueerror
Invalid template for condition
validation error python, validation, jinja2, router
Refusing to deserialize
exception critical serialization, security, deserialization
The generated summary did not reduce the conversation size
exception error llm, summary, token-budget, runtime, compaction
Could not import
exception error python, import-error, deserialization, haystack
Maximum run count reached for component
exception error haystack, pipeline, infinite-loop, cycle
Invalid value for word_count_threshold
validation error python, validation, ranker, constructor-argument
Failed to perform conversion between components:\nSender…
exception error haystack, pipeline, type-conversion, runtime
Please provide an Azure endpoint or set the environment…
validation critical python, azure, configuration, env-var, missing-credential
Input must be a dictionary or a list of dictionaries.
validation error haystack, json-schema, validation, type-error
Refusing to deserialize an OutputAdapter with unsafe=True…
exception critical python, haystack, deserialization, security, sandbox-escape
The Mermaid server response does not look like a valid
exception error network, security, mermaid, content-validation
Component ' ' (name: ' ') not imported. Please check that…
exception error serialization, import, missing-package, pipeline, haystack
Error dumping pipeline to YAML - Ensure that all pipeline…
exception error python, yaml, serialization, pipeline
Function ' ': parameter ' ' does not have a type hint.
exception error type-hints, tool-definition, python, validation
A component named ' ' already exists in this pipeline…
validation error python, pipeline, naming-conflict
Component has already been added to this Pipeline under the…
exception error python, pipeline, api-misuse
'value' key missing in
exception error haystack, filters, filtererror, missing-key
MockDocumentEmbedder expects a list of Documents as…
exception error type-error, mock, documents, python
The ' ' expression must evaluate to a ChatMessage or a list…
validation error jinja2, chat-template, type-mismatch
secondary_split_overlap must be non-negative.
validation error python, validation, constructor-argument, haystack
Invalid template for condition
validation error router, jinja, validation, type-mismatch
' ' resolves outside the store root ' '.
validation error python, security, path-traversal, validation
Items in the tools list must be Tool or Toolset instances.
exception error serialization, type-check, toolset
Combining Toolsets and Tools with '+' is deprecated and…
console warning deprecation, toolset, operator-overloading, python
Missing 'type' in serialization data
exception error deserialization, yaml, pipeline, missing-field
Variable ' ' from conflicts with input names in the run…
validation error encoding, skill-store, file-type, utf-8
Invalid pipeline snapshot from
exception error pipeline, resume, deserialization, validation
pop from empty queue
exception error queue, indexerror, concurrency, internal-api
Error loading pipeline from YAML - Ensure that all pipeline…
exception error python, yaml, serialization, pipeline
Error while unmarshalling serialized pipeline data. This is…
exception error python, serialization, pipeline
Paper size must be a string (e.g., 'a4', 'a3').
validation error python, validation, mermaid, pipeline-drawing
Unknown link format ' '. Supported formats are
validation error python, valueerror, enum, invalid-argument
Variable ' ' from is already defined in the state schema…
validation error filenotfound, skill-store, filesystem, path
Output type specifications of 'run' and 'run_async' methods…
exception error haystack, component, output-types, run-async, componenterror
Pass either 'embedding' or 'embedding_fn', not both.
validation error configuration, mock, python, parameters
CSVToDocument: quotechar must be a single character.
validation error python, csv, configuration, valueerror
Variadic input ' ' must have a type argument, e.g…
exception error python, typing, generics, component-inputs, haystack
Connection must have both sender and receiver
exception error pipeline, haystack, connection, partial-resolution
OpenAIDocumentEmbedder expects a list of Documents as…
exception error type-error, openai, documents, python
Refusing to deserialize
exception critical security, deserialization, builtins-blocked
Some provided documents are not textual…
validation error python, ranker, documents, content-validation
All chat generators failed. Last error: . Failed chat…
exception error fallback, runtime-error, api-failure, all-generators-failed
No `jq_schema` nor `content_key` specified. Set either or…
validation error python, haystack, json-converter, configuration
Refusing to deserialize an OutputAdapter with custom…
exception critical python, haystack, deserialization, security, arbitrary-code-execution
Serialization of instance methods is not supported.
exception error python, serialization, callable, haystack
Variable ' ' not found in inputs for passthrough route ' '…
exception error router, missing-variable, pipeline-wiring
Couldn't deserialize component
exception error serialization, deserialization, pipeline, haystack
Missing 'type' in serialization data
exception error deserialization, haystack, python
tools must be a list of Tool and/or Toolset objects, a…
validation error python, type-validation, agent, tools
A file path must be provided in 'csv_file' parameter to…
validation error python, csv, argument-validation
Refusing to deserialize
exception error serialization, security, type-annotation
The embedding size of all Documents should be the same…
exception error embeddings, dimension-mismatch, document-store
Invalid Jinja template
validation error python, haystack, jinja, template-syntax, output-adapter
expected token 'assign', got ...
panic error python, jinja2, template-syntax, haystack
Hook registered for hook point
validation error yaml, skill-store, frontmatter, type-error
Invalid pipeline snapshot: components
validation error haystack, pipeline, snapshot, validation
Unsupported document_comparison_field
validation error python, value-error, evaluators, configuration
For compatibility with the Hugging Face API, a…
validation error haystack, hugging-face, chatmessage, valueerror, tool-call-result
Refusing to deserialize a ConditionalRouter with custom…
exception error deserialization, security, jinja, safe-mode
`context_window` must be a positive number of tokens, got
validation error validation, constructor, config, compaction
`max_total_tokens` must be a positive number of tokens, got
validation error python, agent, argument-validation, configuration
Missing mandatory input
validation error haystack, pipeline, validation, missing-input
No unused ToolExecutionDecision matches tool call
validation error python, validation, hooks, human-in-the-loop, tools