Better migration errors#640
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The new error messages provide more context and make sure to mention that ppxlib raised the error. Signed-off-by: Patrick Ferris <patrick@sirref.org>
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Apr 24, 2026
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Looks good to me! Only have a minor suggestions on the decoding failure message.
The formatting looks good enough to me, we can always improve it later on.
| Format.sprintf | ||
| "ppxlib invalid encoding: %s\n\n\ | ||
| Ppxlib failed to decode a feature from the OCaml %s AST. If this does \ | ||
| not seem right, please do open an issue at \ |
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How about also hinting at an interaction between the language feature and a ppx here?
Something along those lines:
This is likely caused by the use of a 5.3+ language feature within code directly interpreted by a ppx.
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Maybe even add something like:
If you'd like this feature to be supported by the ppx involved, please reach out to the ppx maintainers.
If this does not seem right, please do open an issue at...
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The new error messages provide more context and make sure to mention that ppxlib raised the error. My
Format-knowledge is not great so perhaps there is something better thanpp_print_text. Also, very happy to discuss what the "better error messages" should be @NathanReb !Part of improving #626