What exactly does "installing a package" mean?

What exactly does "installing a package" mean?

[Marcin Borkowski]

Hi all,

do I get it correctly that "installing a package" means that Emacs
creates a certain subdirectory of `package-user-dir' and puts the
relevant file(s) there - and that's it?

In particular, is deleting a subdirectory of `package-user-dir' enough
to uninstall the package?  Is moving its subdirectory somewhere else,
restarting Emacs, then copying it back again and restarting again
equivalent to uninstalling and then installing again?

The reason I'm asking is that I'd like to get rid of the mess I managed
to introduce in `package-user-dir', but OTOH this mess is working, and
I don't want to break something accidentally, or rather, I want to have
a simple way to rollback any changes.

TIA,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: What exactly does "installing a package" mean?

[Kevin W. van Rooijen]

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Hi Marcin,

Installing a package /usually/ refers to installing a package through
the Emacs built in package manager.
http://www.emacswiki.org/emacs/InstallingPackages

These packages get installed in the 'package-user-dir', you yourself
should not have to manually modify any contents in that directory.
If you want to try and clean up your package management I suggest
taking a look at
use-package https://github.com/jwiegley/use-package
and Melpa https://github.com/milkypostman/melpa

Installing a package manually would mean adding the path to your package
to our load-path, and then require it manually. Though looking into
Emacs' built-in package manager is worth the effort.

So instead of removing them from your package-user-dir manually, try adding the
packages you need through use-package and let your Emacs configurations
handle it for you.

Marcin Borkowski writes:

> Hi all,
>
> do I get it correctly that "installing a package" means that Emacs
> creates a certain subdirectory of `package-user-dir' and puts the
> relevant file(s) there - and that's it?
>
> In particular, is deleting a subdirectory of `package-user-dir' enough
> to uninstall the package?  Is moving its subdirectory somewhere else,
> restarting Emacs, then copying it back again and restarting again
> equivalent to uninstalling and then installing again?
>
> The reason I'm asking is that I'd like to get rid of the mess I managed
> to introduce in `package-user-dir', but OTOH this mess is working, and
> I don't want to break something accidentally, or rather, I want to have
> a simple way to rollback any changes.
>
> TIA,


- --

Kevin W. van Rooijen
@attichacker
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Re: What exactly does "installing a package" mean?

[Marcin Borkowski]

On 2015-10-26, at 22:31, Kevin W. van Rooijen <kevin.van.rooijen@attichacker.com> wrote:

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> Hash: SHA512
>
> Hi Marcin,
>
> Installing a package /usually/ refers to installing a package through
> the Emacs built in package manager.
> http://www.emacswiki.org/emacs/InstallingPackages
>
> These packages get installed in the 'package-user-dir', you yourself
> should not have to manually modify any contents in that directory.
> If you want to try and clean up your package management I suggest
> taking a look at
> use-package https://github.com/jwiegley/use-package
> and Melpa https://github.com/milkypostman/melpa
>
> Installing a package manually would mean adding the path to your package
> to our load-path, and then require it manually. Though looking into
> Emacs' built-in package manager is worth the effort.
>
> So instead of removing them from your package-user-dir manually, try adding the
> packages you need through use-package and let your Emacs configurations
> handle it for you.

Thanks, but you misunderstood me.  What I was asking about was
a particular /implementation detail/ of Emacs' package manager.

I've already added some packages - in fact, I'm afraid too many of them,
from too many repositories - and I want to clean the mess.  However,
that mess is currently working, and if something goes wrong with the
cleaning, I want to be able to quickly recover.  Doing manual
manipulations in `package-user-dir' seems the easiest way.

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: What exactly does "installing a package" mean?

[Emanuel Berg]

Marcin Borkowski <mbork@mbork.pl> writes:

> On 2015-10-26, at 22:31, Kevin W. van Rooijen
> <kevin.van.rooijen@attichacker.com> wrote:

OT: Did you get that as a private mail? I don't see it
in the gmane.emacs.help threads...

> Thanks, but you misunderstood me. What I was asking
> about was a particular /implementation detail/ of
> Emacs' package manager.
>
> I've already added some packages - in fact, I'm
> afraid too many of them, from too many repositories
> - and I want to clean the mess. However, that mess
> is currently working, and if something goes wrong
> with the cleaning, I want to be able to quickly
> recover. Doing manual manipulations in
> `package-user-dir' seems the easiest way.

As always: this "clean" and dirty and "mess" and
minimal and bloated etc. etc. is based on
a misconception that is derived from the physical
world. In the physical world, things that are
sometimes useful, but not often enough, or perhaps not
right now, such things may get in the way, and you
might consider putting other stuff there, instead.

OTOH, in a computer system, it doesn't work like that
at all. If the computer is well-organized, there is no
mess in having one zillion packages or binaries or
shell functions or scripts, or all of that at the same
time, as long as they all

    1) work, and

    2) serve a specific purpose

They don't get in the way; they don't interfere with
each other; and, you never know when you might need
them. So *keep* the "mess"!

That said, with Emacs you basically need a bunch of
.el files which you can just as well load manually.
They can be compiled if you wish.

If you use a package manager then the whole point of
having one of those is when you don't want to do stuff
manually. To install stuff with the package manager,
and then remove it manually or otherwise alter it
manually, I can't see that leading to anything but
inconsistency and confusion...

But, to answer your question, no, there is nothing to
it but files and directories, just like everything
else on a Unix system. So alter it all exactly like
you please. Only, especially since it works, I don't
see any gain in doing so - on the contrary it'll be
error-prone and time-consuming. Only if you enjoy it
you should do it.

-- 
underground experts united
http://user.it.uu.se/~embe8573

Re: What exactly does "installing a package" mean?

[Kevin W. van Rooijen]

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Emanuel Berg writes:

> Marcin Borkowski <mbork@mbork.pl> writes:
>
>> On 2015-10-26, at 22:31, Kevin W. van Rooijen
>> <kevin.van.rooijen@attichacker.com> wrote:
>
> OT: Did you get that as a private mail? I don't see it
> in the gmane.emacs.help threads...

Strange, I CC'd the mailing list..

> But, to answer your question, no, there is nothing to
> it but files and directories, just like everything
> else on a Unix system. So alter it all exactly like
> you please. Only, especially since it works, I don't
> see any gain in doing so - on the contrary it'll be
> error-prone and time-consuming. Only if you enjoy it
> you should do it.

I agree with this, in the end having too many packages doesn't really
matter as long as it's managed by Emacs. But of course it's your choice :)

- --

Kevin W. van Rooijen
@attichacker
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Re: What exactly does "installing a package" mean?

[Joost Kremers]

Emanuel Berg wrote:
> But, to answer your question, no, there is nothing to
> it but files and directories, just like everything
> else on a Unix system.

Well, that's a bit of a naive statement. Of course it's all files and
directories, the question is, *which* files and directories. If Emacs
were to keep a list of installed packages and would save this list to,
say, `~/.emacs.d`, then it would still be "all files and directories",
but as an Emacs user, you might still run into trouble if you delete a
package from `package-user-dir` but do not update the file containing
the list of installed packages.

For example, if you remove the files of a package xyz on a
Debian(-based) system, dpkg will still think xyz installed, because its
own database still says it is.


-- 
Joost Kremers                                   joostkremers@fastmail.fm
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)

Re: What exactly does "installing a package" mean?

[Emanuel Berg]

Joost Kremers <joost.m.kremers@gmail.com> writes:

> Well, that's a bit of a naive statement. Of course
> it's all files and directories, the question is,
> *which* files and directories. If Emacs were to keep
> a list of installed packages and would save this
> list to, say, `~/.emacs.d`, then it would still be
> "all files and directories", but as an Emacs user,
> you might still run into trouble if you delete
> a package from `package-user-dir` but do not update
> the file containing the list of installed packages.
>
> For example, if you remove the files of a package
> xyz on a Debian(-based) system, dpkg will still
> think xyz installed, because its own database still
> says it is.

In general, there are many reasons to use a package
manager, notably reduced complexity and convenience
(those two are perhaps the same thing).

In general, there are a couple of reasons *not* to use
a package manager, notably (eventually) better
understanding and control (those two are perhaps the
same thing).

Talking specifically, on a Debian system or fork, I'd
strongly advice against not using apt-get or aptitude,
because that works so well and the strength of Debian
is (except for its Unix architecture which it shares
with all Linux distros) - the strength of Debian is
the immense and well-maintained software repositories,
exactly those which you browse and extract software
from with aptitude!

Talking specifically, on an Emacs system, I mean in
Emacs, the package situation is much less complicated
than on a Debian system. There is inline documentation
instead of separate manpages and info-files. There is
a userspace directory instead of the plethora of
directories holding binaries on a Unix system. Also,
Emacs relies to a much lesser degree on package
software than does a Debian system, which would be
crippled without the dear repos next door.

As, in Emacs, the packages are just a bunch of Elisp
files, while using a package manager is as well, if
you want to do stuff manually with `provide',
`require', `load-path', `batch-byte-compile' - this is
fine as well! (You can even do both.)

Mixing it up (package manager and manual edits) for
the same package/source file(s) tho is the one thing
I wouldn't recommend.

-- 
underground experts united
http://user.it.uu.se/~embe8573

Re: What exactly does "installing a package" mean?

[Stefan Monnier]

> In particular, is deleting a subdirectory of `package-user-dir' enough
> to uninstall the package?

Yes.

> Is moving its subdirectory somewhere else, restarting Emacs, then
> copying it back again and restarting again equivalent to uninstalling
> and then installing again?

Yes.


        Stefan