RE: [gentoo-user] Building packages in different prefix without rebuilding system packages

[Pengcheng Xu]

François-Xavier's first email didn't make its way to my inbox, so I'm replying to this one instead.  EPREFIX is specifically designed for the Gentoo Prefix project [1].  In a word, Portage installs _everything_ inside the prefix, and uses nothing except the kernel (and some user files under home) outside the prefix.  It is widely used in supercomputing and corporate infrastructure where the user does not have escalated permissions and the existing packages are too old or missing (CentOS 5) for whatever the user is trying to do.

What you're trying to achieve sounded a lot like `./configure --prefix=...` to me.  If you're just dealing a small amount of things, I would suggest modifying the ebuild (in a local overlay) and changes where the program installs to.  That means no special handling on Portage's side, just the app's installed to somewhere else rather than the default prefix (in most cases '/usr').

[1]: https://wiki.gentoo.org/wiki/Project:Prefix

Regards,
-- 
Pengcheng Xu
https://jsteward.moe

> -----Original Message-----
> From: Dale <rdalek1967@×××××.com>
> Sent: Thursday, May 14, 2020 1:14 PM
> To: gentoo-user@l.g.o
> Subject: Re: [gentoo-user] Building packages in different prefix without
> rebuilding system packages
>
> François-Xavier Carton wrote:
>
>
> 	Hi,
>
> 	Is there a way of installing packages in a different prefix while still
> 	using system packages? I've tried setting EPREFIX, however doing that
> 	will install all dependencies in the prefix, even if there are already
> 	installed in the system.
>
> 	I was hoping to install some packages in user directories, but I also
> 	don't want to duplicate the packages installed globally. For example,
> 	most packages eventually depend on gcc, which I definitely don't want
> to
> 	compile twice. So ideally, only dependencies that are not installed
> 	globally should be pulled in.
>
> 	I was not able to find a way of doing that, but I feel like it shouldn't
> 	be too hard, because EPREFIX almost does what I want. Does someone know
> 	if it's possible without too much tweaking?
>
> 	Thanks,
> 	-François-Xavier
>
>
>
> I'm clueless on EPREFIX but if you want to avoid compiling a package twice,
> would the -k option help?  If you have portage set to save the binaries you
> compiled before, it would install from that instead of compiling things twice.
>
> Just thought I'd mention just in case it would help.
>
> Dale
>
> :-)  :-)