* fix(skills): surface offending line and quoting hint on SKILL.md YAML errors
When a SKILL.md front-matter fails to parse, the existing log only
echoes PyYAML's raw message, leaving authors to grep the file for the
offending line. This is especially painful for the very common
LLM-authored mistake of an unquoted scalar containing ': '
(e.g. 'description: foo: bar'), which fails with
'mapping values are not allowed here' and silently drops the skill.
Enrich the error log with:
- the source line PyYAML pointed at via problem_mark
- a targeted, copy-pasteable quoting hint when (and only when) the
error is the well-known 'mapping values are not allowed' scanner
error on an unquoted value
The skill is still rejected (no semantics are guessed or rewritten);
only the diagnostic is improved.
Fixes#3333
* improve(skills): address CR feedback on SKILL.md YAML error diagnostics
Per review on #3335:
- Log the file line number (mark.line + 2) instead of the
front-matter-internal line number, so authors land on the right
row in their editor.
- Use exc.problem == "mapping values are not allowed here" for a
tighter match than substring-scanning str(exc).
- Preserve the offending key's leading whitespace in the quoting
hint so nested mappings stay nested when authors paste the fix
back.
- Rewrite the regression test to actually exercise the new
behaviour: PyYAML's own message already echoes the offending
line (and truncates it with "..."), so the old assertion
passed on main. New assertions pin (a) the file-line number,
(b) the full untruncated line, and (c) the copy-pasteable hint.
- Add a guard test for nested-key indentation so the
partition()/strip() shape cannot regress silently.
Refs #3333, #3335
* fix(skills): escape backslashes in YAML quoting hint
The hint emitted by _format_yaml_error previously escaped only double
quotes, so values containing backslashes (e.g. Windows paths like
C:\Temp or regex escapes like \d) produced a suggested scalar that
was either invalid YAML or silently re-interpreted by PyYAML's
double-quoted escape rules when pasted back. Escape order matters:
backslashes first, then double quotes.
Adds two regression tests covering Windows-path and regex-style
backslashes.
Address Copilot CR feedback on PR #3335.
89ae74d4f4