[OE-core] FETCHCMD drop breaks build when append is used (from patch b259bd31eb)

[Andre McCurdy]

On Fri, Aug 30, 2019 at 3:08 AM Andrey Zhizhikin <andrey.z at gmail.com> wrote:
>
> Hello Andre,
>
> I've just pulled the master and experienced a build failure during
> fetching of updated recipe's source tarballs.
>
> The reason for this being that defaults for FETCHCMD has been dropped
> with your patch b259bd31eb from the series. Once defaults are removed
> and appends are used - the FETCHCMD gets defined to the value listed
> in append, which normally does not contain a command itself rather
> than necessary additional parameters (like user/passwd if working with
> local pre-mirror servers).

I think for the specific case of usernames and passwords the advice
would be to put them in .netrc etc rather than trying to append to the
fetcher command lines (but mainly for security reasons rather than
this issue).

> This patch would also break several other recipes which are using
> appends to FETCHCMD, for example for FETCHCMD_wget the libedit would
> fail since it appends the wget to use different User-Agent.
>
> I've copied Raj here since he introduced this recipe in the form it is
> and would definitely break.
>
> Can you please have a look at this and advise on how one can continue
> to use the FETCHCMD appends for the future?

One answer could be that modifications of the fetcher command lines
should be done by completely defining them rather than appending. I'm
not sure how reasonable that is though.

In the end the approach to fixing this depends on whether appending to
the default fetcher commands is considered valid usage or not... and I
don't know the answer to that.

> For now, I've defined the FETCHCMD_wget in my local.conf but I do not
> believe that this is the general way everyone should follow if they
> would need to append fetcher commands...
>
> Thanks a lot!
>
> --
> Regards,
> Andrey.