[pacman-dev] Alternatives system brainstorm

[Allan McRae]

On 19/10/19 9:57 pm, Daan van Rossum wrote:
> * on Saturday, 2019-10-19 18:15 +1000, Allan McRae <allan at archlinux.org> wrote:
> 
>> /bin/sh -> bash/dash
>> /usr/bin/awk -> gawk/nawk
>> /usr/bin/cc -> gcc/clang
> 
> Can we provide alternatives by means of sets of mutually exclusive link packages, using package properties that are already supported in pacman?
> 
> sh-bash
> 	provides=('sh')
> 	depends=('bash')
> 	conflicts=('sh-dash')
> sh-dash
> 	provides=('sh')
> 	depends=('dash')
> 	conflicts=('sh-bash')
> bash
> 	depends('sh')
> dash
> 	depends('sh')
> 

Sure - or we could have a system to handle it in a less obtuse manner...

What happens when a new package wants to provide "sh"?   We need to
rebuild sh-bash and sh-dash?  Easy enough, except that assumes that all
three packages are packaged by the same group.  If bash and dash are
packaged by a distro and the new package by a third party, then the
conflicts provided by the distro are not enough.  But an alternatives
system would work.