[arch-general] How to "decorate" a package build?

[Peter Nabbefeld]

Am 08.03.2017 um 11:55 schrieb ProgAndy:
> Am 08.03.2017 um 11:45 schrieb Peter Nabbefeld:
>>
>> Hello,
>>
>> is it possible to decorate a package build, i.e. set some prconditions
>> (like exporting variables) and probably even change the build process
>> (compile instead of copying just the binaries)?
>>
>> E.g., to modify the firefox package update to first compile with
>> "--enable-alsa". Of course, I would have to create my own package in a
>> private repository. The new PKGBUILD file would need to refer the
>> original one, to get e.g. the package version number. However, the
>> private package would always have the same version, so the official
>> package change needs to be hooked to the generic private package:
>>
>> Official Package Changed --«Signal»--> Private Package Update
>> --«Inherits»--> Official Package Update
>>
>> Kind regards
>> P.
>
> Hello,
>
>
> That is impossible with pacman.
>
> What you can do is create a local repository that is included in the
> automatic pacman upgrade. Then write a shell script that checks for
> updates of the arch package, merges it with your local changes, build it
> and add it to the repository. You should change the package name with
> e.g. a prefix or suffix and add the original package as a conflict to
> make it work properly. Now your custom version is available for the next
> pacman upgrade.
>
>
> --
>
> A.
>

I've found out I could probably use PreTransaction-Hooks, but I cannot 
see, when exactly the hook is executed: before download, after download, 
or after unpacking.

Regards
P.