bug#41602: texlive-texmf is actually subtitutable

[Leo Famulari]

On Fri, May 29, 2020 at 05:15:40PM +0200, Ludovic Courtès wrote:
> The info suggests it won’t be substituted, but it’s eventually
> substituted.  I wonder why, because the .drv has:
> 
>   ("allowSubstitutes","0")
> 
> and the daemon has:
> 
>   bool substitutesAllowed(const Derivation & drv)
>   {
>       return get(drv.env, "allowSubstitutes", "1") == "1";
>   }
> 
> and:
> 
>   if (settings.useSubstitutes && substitutesAllowed(drv))
>       foreach (PathSet::iterator, i, invalidOutputs)
>           addWaitee(worker.makeSubstitutionGoal(*i, buildMode == bmRepair));
> 
> Thoughts?

I wonder if the content-addressed fallbacks take a different code path
that doesn't respect "allowSubstitutes"?