[git-buildpackage] could gbp.config.GbpOptionParser.get_config_files handle GBP_CONF_FILES=''

[Nish Aravamudan]

On 11.01.2018 [08:39:10 +0100], Guido Günther wrote:
> Hi Nish,
> On Wed, Jan 10, 2018 at 02:21:52PM -0800, Nish Aravamudan wrote:
> > For the reproducibility/debuggability of the git-ubuntu snap, we want to
> > ensure that everyone will end up running certain commands (e.g., quilt,
> > gbp) the same, no matter what their local configuration is. This is
> > especially true for the importer itself, but is also true for other
> > subcommands in our case.
> > 
> > I wonder if it might be reasonable to do:
> > 
> > diff --git a/gbp/config.py b/gbp/config.py
> > index 8acf15da..c2feb2ab 100644
> > --- a/gbp/config.py
> > +++ b/gbp/config.py
> > @@ -409,7 +409,7 @@ class GbpOptionParser(OptionParser):
> >          >>> if conf_backup is not None: os.environ['GBP_CONF_FILES'] = conf_backup
> >          """
> >          envvar = os.environ.get('GBP_CONF_FILES')
> > -        files = envvar.split(':') if envvar else [f for (f, _) in cls.def_config_files]
> > +        files = envvar.split(':') if envvar is not None else [f for (f, _) in cls.def_config_files]
> >          files = [os.path.expanduser(fname) for fname in files]
> >          if no_local:
> >              files = [fname for fname in files if fname.startswith('/')]
> > 
> > This would allow environments that wish to disable config file parsing
> > (and thus behavioral variability) to juset set GBP_CONF_FILES='' rather
> > than to something like '/dev/null' (which seems to be the only choice
> > currently)?
> 
> Isn't it be more explicit to have GBP_CONF_FILES=/does/not/exist or
> GBP_CONF_FILES=/dev/null than to make a distinction between unset or
> set to the empty string? I'd rather not change the current behaviour.

I'm not sure, right now the behavior with GBP_CONF_FILES='' is
surprising -- it seems like it should mean no files are parsed, but
currently it means all the normal files are parsed.

-- 
Nishanth Aravamudan
Ubuntu Server
Canonical Ltd