bug#30130: Add ‘guix whereis’ command

bug#30130: Add ‘guix whereis’ command

[Mathieu Lirzin]

Hello,

I would find really useful if Guix was providing a tool similar to what
‘dnf whatprovides’ or ‘apt-file’ does.  I mean something to check what
packages provides a particular file (executable/manual/library).

My main use-case is when running a ‘configure’ script which checks an
arbitrary program, I would like ‘guix whereis’ to help me find out what
package I need to install to satisfy its configuration requirement.

-- 
Mathieu Lirzin
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bug#30130: Add ‘guix whereis’ command

[Ludovic Courtès]

Mathieu Lirzin <mthl@gnu.org> skribis:

> I would find really useful if Guix was providing a tool similar to what
> ‘dnf whatprovides’ or ‘apt-file’ does.  I mean something to check what
> packages provides a particular file (executable/manual/library).

This has been discussed before, and can be summarized this way:

  1. Finding files that are already in your store could be done easily,
     using ‘updatedb’ or something similar.

  2. Finding files from packages not in your store is trickier: it
     involves getting info from a build farm server typically.

If we address #1 in a Guix-specific way (automatically populating a file
database upon build completion), then perhaps we could arrange for ‘guix
publish’ to publish that info.

Ludo’.

bug#30130: Add ‘guix whereis’ command

[swedebugia]

Hi

This could be solved by a new field in the package-record: (provides
'("list of commands provided"))

What do you think?

This could allow us to quickly let guile search the list of provided
commands and return the package name.

E.g. right now in my guixsd I have no "file" command. I have no idea
which package installs it. :p

-- 
Cheers 
Swedebugia

bug#30130: Add ‘guix whereis’ command

[Ricardo Wurmus]

> This could be solved by a new field in the package-record: (provides
> '("list of commands provided"))

The danger with doing this in a package definition is that it can easily
go out of sync unless we also add a verification phase to compare the
output with the list of provided executables.  Another problem is that
the list might not be complete and it is yet another manual thing to
maintain for all packages.

Another approach is to shift this task to substitute servers.

> E.g. right now in my guixsd I have no "file" command. I have no idea
> which package installs it. :p

The confusingly named “file” package provides the “file” executable ;)

--
Ricardo

bug#30130: Add ‘guix whereis’ command

[Efraim Flashner]

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On Mon, Dec 17, 2018 at 01:03:38PM +0100, Ricardo Wurmus wrote:
> 
> > This could be solved by a new field in the package-record: (provides
> > '("list of commands provided"))
> 
> The danger with doing this in a package definition is that it can easily
> go out of sync unless we also add a verification phase to compare the
> output with the list of provided executables.  Another problem is that
> the list might not be complete and it is yet another manual thing to
> maintain for all packages.
> 
> Another approach is to shift this task to substitute servers.

This is Debian's aproach, with 'apt-file'. Another option that would
keep it more local would be a custom updatedb command that would look in
bin/sbin/libexec in the store for binaries and keep track of that. The
downside of course being that you'd only know about binaries you had in
your store.

> 
> > E.g. right now in my guixsd I have no "file" command. I have no idea
> > which package installs it. :p
> 
> The confusingly named “file” package provides the “file” executable ;)

This works for file, but it's not obvious that 'clear' is in ncurses.

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bug#30130: Add ‘guix whereis’ command

[Ricardo Wurmus]

I’m closing this because we now have “guix locate”.

-- 
Ricardo