The spec defines a number of special identifiers that can be used within layout and other types of qualifiers. These are technically not keywords and can be used as identifiers elsewhere but it's been observed that some drivers (Nvidia does this with packed for example) parse them as actual keywords, producing cryptic errors. While this is a violation of the spec, it would be helpful for Iris to warn shaderpack developers of this behavior in debug mode.

Iris could have a list of these identifiers (see the spec for details) and then warn the user in the log when any identifier matches any string from this list in debug mode. The debugging.md documentation should be updated to mention this feature and provide elaboration.