Misleading failure analysis when jOOQ's DSLContext is unavailable due to R2DBC taking precedence over JDBC

[wilkinsona]

We'll improve this in 2.6 by requiring both the R2DBC SPI and a ConnectionProvider on the classpath before R2DBC is auto-configured. This will prevent jOOQ 3.15's dependency on the R2DBC SPI from inadvertently disabling JDBC auto-configuration and, therefore, our auto-configuration of jOOQ. In the meantime, it would be good if we could improve the current diagnostics which are a bit misleading.

Typically, the failure will look like this:

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APPLICATION FAILED TO START
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Description:

Parameter 0 of method runner in com.example.demo.Application required a bean of type 'org.jooq.DSLContext' that could not be found.


Action:

Consider defining a bean of type 'org.jooq.DSLContext' in your configuration.

In most cases, defining a DSLContext bean won't be the simplest solution. Instead, it would be better to detect that R2dbcAutoConfiguration is active, explain that our jOOQ auto-configuration only supports JDBC and suggest excluding R2dbcAutoConfiguration for those trying to use jOOQ and JDBC or configuring jOOQ manually for those trying to use jOOQ and R2DBC.