docspp check and astro build report two kinds of message. An error stops the build. A warning is printed and the build carries on, unless you run docspp check --strict.
Every message starts with file:line:column. Open that spot first.
diagrams/checkout/diagram.yaml:5:3 error Unknown key "titel"
Message
Cause and fix
A YAML parser message, such as Nested mappings are not allowed in compact mappings
The file is not valid YAML. The usual cause is an unquoted colon or comma in a value, such as title: Before: a long row. Quote the value.
Unknown key "titel" or Unknown keys "a", "b"
A typo, or a key that does not exist. The hint suggests the closest key; the schema lists the allowed ones.
Invalid input: expected string, received undefined
A required field is missing at the path the message names.
Invalid option: expected one of "request"|"response"|...
The value is not one of the allowed ones. Check the spelling against the reference .
A scenario needs steps or phases
The scenario has a title and nothing to play.
Not a recognised step
A step is not a -> b: label, at node: label or par: with a list. Check the arrow and the spacing.
Message
Cause and fix
Node "x" is in unknown group "g"
in: names a group that does not exist. The hint suggests the nearest.
Group "x" is in unknown group "g"
The same, on a group.
Groups are nested in a cycle at "x"
A group’s in: chain loops back on itself.
"x" is not a direct member of group "g"
An entry in a group’s rows: is not a node or group whose in: is that group.
"x" appears in rows twice
The same id is listed twice in rows:.
Edge from "x" is not a node / Edge to "x" is not a node
A typo or an undeclared node. The hint names the nearest id.
Edge id "e" is used twice
Give edges distinct ids, or drop the ids.
Unknown edge kind "x"
Use a built-in kind or define it under edgeKinds:. The hint lists the known kinds.
Message
Cause and fix
"x" is not a node or group
An entry in a view’s include or exclude does not exist.
Scenario "s" uses unknown view "v"
view: names a view that does not exist.
"x" is not a node
A step, via or lanes entry names a node that does not exist.
Node "x" is not in view "v"
The scenario plays on a view that leaves the node out. Add it to the view’s include, or set the scenario’s view:.
No path from "a" to "b" in view "v"
No chain of edges joins them. Declare an edge between them (it can be hidden: true), or add via: through nodes that are connected.
A step with at needs a label or a title
at x: needs text: at x: what happens.
Node "x" is already in lane N
A node is listed in two story lanes.
Scenario "s" is defined twice
The id exists in diagram.yaml and in scenarios/s.yaml.
Message
Cause and fix
Unknown icon "x"
Run docspp icons search x, then use a suggested name.
Icon file "x" was not found or is not an SVG
A ./path.svg icon that does not exist. Paths are relative to the diagram folder.
Unknown node kind "x"
Use a built-in kind or add it under kinds:. The hint suggests the nearest.
Doc file "x" was not found
A doc: path that does not exist. Paths are relative to the diagram folder.
Edge connects a node to itself and is not drawn
A self-edge. Use a self step in a scenario to show a node acting on itself.
"x" appears in the story but is in no lane; it gets its own lane at the end
A lanes: list that leaves out a node the scenario uses. Add it to a lane, or ignore the warning.
Node "x" cites "path", which does not exist
A refs: path that moved. Update the diagram or the reference. Only docspp check reports this.
Fix the first error first
One mistake often causes several messages. A typo in a node id produces an error at every edge and step that uses it. Fix the first, run the check again, and the rest usually disappear.
Symptom
Check
Diagram errors: and a failed build
Run docspp check. The build fails on any diagram error, by design.
<Diagram name="x"> does not match a diagram
The folder name is different. The error lists the names that exist.
The diagram shows “Loading diagram…” and never appears
A browser console error. Is react() from @astrojs/react in astro.config.mjs?
The page is narrow and the diagram tiny
Add @packagelab/docspp-astro/starlight.css to Starlight’s customCss.
Fonts differ from the screenshots
The starter uses IBM Plex through Fontsource. Add it, or set --docspp-sans and --docspp-mono.
Edits to a diagram do not show in pnpm dev
Save the file again. If the compiler itself changed after an upgrade, restart the dev server.