[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: What do you wish for in an package manager? Here you are!

Petr Èech wrote:
>Adam Lazur wrote:
>> The ability to install more than one version of a package simultaneously.
>Hmm. SO you install bash 2.04-1 and bash 2.02-3. Now what will be /bin/bash
>2.04 or 2.02 version? You will divert both of them and symlink it to the old
>name - maybe, but but how will you know, to what name it diverts to use it?
>Give me please 3 sane examples, why you need this. And no, shared libraries
>are NOT an excuse for this.

I or my University needs such a functionallity:

We use already such a system under Solaris which you can find on

This works quite well for us with Solrais, but we have to recompile each
Package, we want to install...

As Debian has already a large Number of Packages it would be impracticle
for us to do all the work again... So why not let the Package Mangement
do it...

O.K. Here are a few examples, why we need such system...
Our Software is installed on decentarlized fileserveres for many Useres
whith different tasks and projects.

The Sys-Admin can not be able to check if an old version is still needed
or if someone dislikes the new Version, here are some User-Space
Programms, which will or would have produced Problems due to a lag of
compatibility with older Versions
You cannot use some Version of Documents created with lyx 1.3 in 1.5 as
the file Format has changed at some Places, while the unknown users
which have to use such a Programm are not able to fix their Problems on
their own. Or they have not enough time to port their Files to new
Version, so if the Sysadmin would have killed the older Version and
replaced with the new one some projects would have had more work than
switching to the new Version....

Think of some gcc versions... you used a trick to get Your programm
work, and then some Specifications changed and your Programm will not
compile any more...
This could be your Diplomatheses which could be in Danger!

Or Gimp us not able any longer to read gifs, but some users don't know
any other program, but want to use gif, so they can use the older

Or the User-Interface has been changed and the User is not willed or has
not the time to learn the User-Interface of the new Version....

Some users might want to live on the bleading edge and others want to
have their version forever, and others want stable well tested Versions
of programms...

And the users like our Module-system and they miss it on Debian...

I hope this are enogh Arguments for a Modulesystem  (whith different
Versions installed)

The current module System has one big disadvantage, it uses the PATH
environment for version switching, and as the space in the enviroment is
very limited we use env-Modules Modules which kontain many other
If we would like to konvert Debian Packages to Modules we only could
load about 14 Modules and then our Path becomes too long. So we would
still have to rebuild env-Packages...

A new Idea from me is, let the Module System create Symlinks under the
Users Home directory to Programms and Libaries Docs he wants to execute
or to see, then the Path and LD_Path  is very short...

A typical link would look like this

/home/use/.Modules/usr/bin/emacs ->

				Here would the standard Debian Package be extracted

The Addition of a Module would mean:
Check for Package Dependencies and install/remove them first... (Ask the
User, to do this!)
Link all Files of the Package to the User's Homedircetory

The Removement of a Module would mean:
Check Module Dependencies, aks if some other Modules should also be
Look at the ModuleDirectory and unlink all files from the User's

This Method has three disatvanages...
1) It need Symlinks which could be expensive on Systems with 1000 Users
and 1000 Programmms (Files)
2) It only works on a per User Base and not on a per Shell Base (which
is sometimes confusing the Users)
3) Not Standard Conformant

But some big Advantages
1) No need For reloading all the Modules again and again
2) No need for Recompilation or Modification of Debian-Packages...
3) Should work right out of the Box

What do you think?

 Thorsten Wilmer

Reply to: