derivedFrom for field enumerations produces error

When trying to use the derivedFrom attribute on an enumeration an error is thrown

svd2ada --boolean --gen-uint-always --no-vfa-on-types --gen-uint-always -o STM32 -p STM32_SVD STM32F439x.svd
raised CONSTRAINT_ERROR : enumerate 'derivedFrom' is not known: MODER15.MODEREnumVals

svd2ada --boolean --gen-uint-always --no-vfa-on-types --gen-uint-always -o STM32 -p STM32_SVD STM32F439x.svd
raised CONSTRAINT_ERROR : enumerate 'derivedFrom' is not known: MODER.MODER15.MODEREnumVals

svd2ada --boolean --gen-uint-always --no-vfa-on-types --gen-uint-always -o STM32 -p STM32_SVD STM32F439x.svd
raised CONSTRAINT_ERROR : enumerate 'derivedFrom' is not known: GPIOK.MODER.MODER15.MODEREnumVals

svd2ada --boolean --gen-uint-always --no-vfa-on-types --gen-uint-always -o STM32 -p STM32_SVD STM32F439x.svd
raised CONSTRAINT_ERROR : enumerate 'derivedFrom' is not known: MODEREnumVals

an example derivedFrom attribute for the last error the is as follows

<enumeratedValues derivedFrom="MODEREnumVals">

example enumerated value

<enumeratedValues> <name>MODEREnumVals</name> <enumeratedValue> <name>Input</name> <description>Input (reset state)</description> <value>0</value> </enumeratedValue> <enumeratedValue> <name>GP_Output_Mode</name> <description>General purpose output mode</description> <value>1</value> </enumeratedValue> <enumeratedValue> <name>Alternate_Function_Mode</name> <description>Alternate function mode</description> <value>2</value> </enumeratedValue> <enumeratedValue> <name>Analog_Mode</name> <description>Analog mode</description> <value>3</value> </enumeratedValue> </enumeratedValues>

Start by reproducing the failure with the supplied svd2ada command and STM32F439x.svd input. Trace handling of enumeratedValues elements with derivedFrom values such as MODEREnumVals and the qualified names shown in the error. Done means these inputs no longer raise the unknown-derivedFrom constraint error and generation completes successfully.