On Fri, 07 Aug 2020 07:33:03 -0400
Julien Lepiller <julien@lepiller.eu> wrote:

> Unfortunately, android-platform-core should first be fixed to accept
> a hash as an argument, otherwise any other version will fail. Don't
> know why we haven't done that before…

I don't understand what the hash would be here, nor the consequences
you describe. Do you have some pointers on the documentation or source
code that I should read to better understand that?

By the way I find it a bit strange to refer to have to manually extract 
android-platform-system-core to be able to refer its include path.

Beside the native-input, this results in the following code:
> #:make-flags (list (string-append "CFLAGS= "
>                                   "-I core/include "
> [...]))
>
> [...]
>
> #:phases
> (modify-phases %standard-phases
> (add-after 'unpack 'unpack-core
>  (lambda* (#:key inputs #:allow-other-keys)
>   (mkdir-p "core")
>    (with-directory-excursion "core"
>     (invoke "tar" "axf" (assoc-ref inputs "android-core")
>             "--strip-components=1"))
>   #t))
> [...])

Instead of just that:
> #:make-flags (list (string-append "CFLAGS= "
>                    "-I " (assoc-ref %build-inputs "android-core")
>                    "/include "))
> [...]))

Another potential improvement would be to remove the
android-platform-version argument completely and set version to it in
android.mk like that:
> (define-public (android-platform-system-core
> [...]
>  (version (android-platform-version))
> [...]

That would make the native-input look like that:
> (native-inputs
>  `(
>    ("android-core" ,android-platform-system-core)))

And if we need the version 9.0.0_r3 we could define a new package:
> (define-public android-platform-system-core-9
>   (package
>    (inherit android-platform-system-core)
>     (version "9.0.0_r3"))))

and use it:
> (native-inputs
>  `(
>    ("android-core" ,android-platform-system-core-9)))

Are both proposal a good idea? Or does it have any downsides that I
didn't think of?

Denis.