How to have a build settings defined in "base", while customising it further in "config/Release"?

[acecilia]

Hi 👋

I have the following spec:

...
settings:
  base:
    OTHER_SWIFT_FLAGS:
      - -Xfrontend
      - -warn-long-expression-type-checking=500
      - -Xfrontend
      - -warn-long-function-bodies=1000

  configs:
    Release:
      OTHER_SWIFT_FLAGS:
        - -Xfrontend 
        - -internalize-at-link
...

The intended behaviour is that:

• For all configurations, OTHER_SWIFT_FLAGS has a value of -Xfrontend -warn-long-expression-type-checking=500 -Xfrontend -warn-long-function-bodies=1000
• For release configuration, OTHER_SWIFT_FLAGS has a value of -Xfrontend -warn-long-expression-type-checking=500 -Xfrontend -warn-long-function-bodies=1000 -Xfrontend -internalize-at-link

The reality (which is somewhat expected) is that:

• For all configurations, OTHER_SWIFT_FLAGS has a value of -Xfrontend -warn-long-expression-type-checking=500 -Xfrontend -warn-long-function-bodies=1000
• For release configuration, OTHER_SWIFT_FLAGS has a value of -Xfrontend -internalize-at-link

Is there any way to achieve the intended behaviour?

Thanks! 🙏

[yonaskolb]

Build settings are currently merged by simply replacing the keys, so this isn't possible right now as far as I'm aware. include specs however are merged by appending arrays to each other as you can read about here https://github.com/yonaskolb/XcodeGen/blob/master/Docs/ProjectSpec.md#include, so this could technically be ported over to build settings, though it would be a breaking change so would probably need an explicit :APPEND specifier similar to the :REPLACE specifier in included specs.

Alternatively you could lean on YAML's anchors and aliases to achieve some level of sharing.