How should mock behave when DNF is not available?

[Miroslav Suchý]

I am working on switching rawhide targets to DNF. However on EL* is DNF 
not available.

Therefore you will not be able to build rawhide packages on EL7- using 
standard mock configuration.

I see several options to offer to user:

1) Discourage user from doing that by providing no hints how to 
workaround it.

2) Tell him that DNF is not available and he must run mock with "--yum" 
option. And warn him that he may get different depsolving.

3) Tell him that DNF is not available and fall back automatically to yum 
and warn him that he may get different depsolving.

Unless somebody will have better idea I would go with (2).

Ideas? Comments?

Mirek

[Josh Boyer]

On Wed, Feb 11, 2015 at 8:51 AM, Miroslav Suchy <msuchy(a)redhat.com&gt; wrote:
>  I am working on switching rawhide targets to DNF. However on EL* is
> DNF not
>  available. 
Mock isn't available on EL* either.  It's in EPEL.

>  Therefore you will not be able to build rawhide packages on EL7-
> using
>  standard mock configuration. 
Can DNF be packaged for EL7- in EPEL and used that way?

>  I see several options to offer to user:
>
>  1) Discourage user from doing that by providing no hints how to workaround
>  it.
>
>  2) Tell him that DNF is not available and he must run mock with "--yum"
>  option. And warn him that he may get different depsolving.
>
>  3) Tell him that DNF is not available and fall back automatically to yum and
>  warn him that he may get different depsolving.
>
>  Unless somebody will have better idea I would go with (2).
>
>  Ideas? Comments? 
If DNF can't be packaged in EPEL, then I would agree option 2 seems to
be the best choice.

josh

[Clark Williams]

On Wed, 11 Feb 2015 08:59:23 -0500
Josh Boyer <jwboyer(a)fedoraproject.org&gt; wrote:

>  On Wed, Feb 11, 2015 at 8:51 AM, Miroslav Suchy
> <msuchy(a)redhat.com&gt; wrote:
>  > I am working on switching rawhide targets to DNF. However on EL* is DNF not
>  > available.
>  
>  Mock isn't available on EL* either.  It's in EPEL.
>  
>  > Therefore you will not be able to build rawhide packages on EL7- using
>  > standard mock configuration.
>  
>  Can DNF be packaged for EL7- in EPEL and used that way?
>  
>  > I see several options to offer to user:
>  >
>  > 1) Discourage user from doing that by providing no hints how to workaround
>  > it.
>  >
>  > 2) Tell him that DNF is not available and he must run mock with "--yum"
>  > option. And warn him that he may get different depsolving.
>  >
>  > 3) Tell him that DNF is not available and fall back automatically to yum and
>  > warn him that he may get different depsolving.
>  >
>  > Unless somebody will have better idea I would go with (2).
>  >
>  > Ideas? Comments?
>  
>  If DNF can't be packaged in EPEL, then I would agree option 2 seems to
>  be the best choice. 
Why not #3? Seems silly to make someone restart the command when we
know that we'll need to use yum.

I'd say just shout loudly that dnf is not available, internally shift
to yum and do the build.

Clark

[Mike Bonnet]

On 2/11/15 6:33 AM, Clark Williams wrote:
>  On Wed, 11 Feb 2015 08:59:23 -0500
>  Josh Boyer <jwboyer(a)fedoraproject.org&gt; wrote:
>
> > On Wed, Feb 11, 2015 at 8:51 AM, Miroslav Suchy <msuchy(a)redhat.com&gt; wrote:
> >> I am working on switching rawhide targets to DNF. However on EL* is DNF not
> >> available.
> >
> > Mock isn't available on EL* either.  It's in EPEL.
> >
> >> Therefore you will not be able to build rawhide packages on EL7- using
> >> standard mock configuration.
> >
> > Can DNF be packaged for EL7- in EPEL and used that way?
> >
> >> I see several options to offer to user:
> >>
> >> 1) Discourage user from doing that by providing no hints how to workaround
> >> it.
> >>
> >> 2) Tell him that DNF is not available and he must run mock with
> "--yum"
> >> option. And warn him that he may get different depsolving.
> >>
> >> 3) Tell him that DNF is not available and fall back automatically to yum and
> >> warn him that he may get different depsolving.
> >>
> >> Unless somebody will have better idea I would go with (2).
> >>
> >> Ideas? Comments?
> >
> > If DNF can't be packaged in EPEL, then I would agree option 2 seems to
> > be the best choice.
>
>  Why not #3? Seems silly to make someone restart the command when we
>  know that we'll need to use yum.
>
>  I'd say just shout loudly that dnf is not available, internally shift
>  to yum and do the build. 
+1

[Miroslav Suchý]

On 02/11/2015 02:59 PM, Josh Boyer wrote:
>  Can DNF be packaged for EL7- in EPEL and used that way? 
I doubt that the work is worth the effort for EPEL5 and 6.

There may even be technical obstacle as on EL5 is very old python (2.4).

At least no one is willing to do that for now.

Mirek

[Miroslav Suchý]

On 02/11/2015 03:33 PM, Clark Williams wrote:
>  Why not #3? Seems silly to make someone restart the command when we
>  know that we'll need to use yum. 
Because I'm afraid that people will ignore warning and then will be 
surprised when they will get different result than previously.

You can always remove that warning/error by removing the line:
   config_opts['package_manager'] = 'dnf'
from
   fedora-rawhide-*.cfg
And mock will be silent. However you should be aware of consequences.

Mirek

[Mike Bonnet]

On 2/11/15 9:58 AM, Miroslav Suchy wrote:
>  On 02/11/2015 03:33 PM, Clark Williams wrote:
> > Why not #3? Seems silly to make someone restart the command when we
> > know that we'll need to use yum.
>
>  Because I'm afraid that people will ignore warning and then will be
>  surprised when they will get different result than previously.
>
>  You can always remove that warning/error by removing the line:
>     config_opts['package_manager'] = 'dnf'
>  from
>     fedora-rawhide-*.cfg
>  And mock will be silent. However you should be aware of consequences. 
Would it make sense to have different .cfg files, without the dnf line, 
for mock on EL*?  This would maintain the current behavior of mock on 
EL* and require no change by users.  It would be pretty easy to sed that 
line out of the .cfg files in %build.

[Miroslav Suchý]

On 02/11/2015 07:23 PM, Mike Bonnet wrote:
>  Would it make sense to have different .cfg files, without the dnf
> line,
>  for mock on EL*? 
Nope.

We will be building Rawhide (and F23) using DNF. All Koji builders and 
on Fedora and DNF is available there.

However if some $USER will run on his local EL6 machine:
   mock -r fedora-rawhide-x86_64 foo.src.rpm
then he may get different result compared to koji.

And it may be even more problematic if he run:
   fedora-review
which use rawhide by default. And build log is usually not reviewed.

Mirek