[Nix-dev] Re: [Nix-commits] SVN commit: nix - 16859 - raskin - in nixpkgs/trunk/pkgs: build-support/builder-defs build-support/upstream-updater development/libraries development/libraries/geoip tools/admin tools/admin/webdruid top-level

[Eelco Dolstra]

Hi,

Michael Raskin wrote:

> Added: nixpkgs/trunk/pkgs/tools/admin/webdruid/src-for-default.nix
> ===================================================================
> --- nixpkgs/trunk/pkgs/tools/admin/webdruid/src-for-default.nix	                        (rev 0)
> +++ nixpkgs/trunk/pkgs/tools/admin/webdruid/src-for-default.nix	2009-08-26 11:13:36 UTC (rev 16859)

I'm not convinced that this auto-updating is "worth it".  Having two extra Nix
expressions for each package adds considerable clutter.  Writing
"src-info-for-default.nix" does not seem particularly easy.  It also seems
rather brittle (i.e. you download a page and scan for something that hopefully
looks like the latest tarball with some regexps, if I understand it correctly -
that's likely to break).

When you update to a new version, it is often necessary to update other parts of
the Nix expression as well; in any case you have to test it.  So updating the
name and hash attributes is only a small part of the effort anyway.

Auto-updating is worth it when you have a large set of packages that all come
from the same source and for which the pertinent package info can be obtained
automatically, e.g., X.org releases, Hackage, CPAN, etc.

BTW, it seems that a lot of auto-update checking can be done globally.  For
instance, you can just scan Nixpkgs for any fetchurl call with a
mirror://sourceforge/<projectname>/<package>.tar... URL and see if Sourceforge
has a newer version of <package>.  No need to specify a
"src-info-for-default.nix" for each package.

-- 
Eelco Dolstra | http://www.st.ewi.tudelft.nl/~dolstra/