From murdoch.duncan at gmail.com  Fri Dec 16 16:14:18 2016
From: murdoch.duncan at gmail.com (Duncan Murdoch)
Date: Fri, 16 Dec 2016 10:14:18 -0500
Subject: [Rd] Upgrading a package to which other packages are LinkingTo
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On 16/12/2016 8:37 AM, Dirk Eddelbuettel wrote:
>
> On 16 December 2016 at 08:20, Duncan Murdoch wrote:
> | Perhaps the solution is to recommend that packages which export their
> | C-level entry points either guarantee them not to change or offer
> | (require?) version checks by user code.  So dplyr should start out by
> | saying "I'm using Rcpp interface 0.12.8".  If Rcpp has a new version
> | with a compatible interface, it replies "that's fine".  If Rcpp has
> | changed its interface, it says "Sorry, I don't support that any more."
>
> We try. But it's hard, and I'd argue, likely impossible.
>
> For example I even added a "frozen" package [1] in the sources / unit tests
> to test for just this. In practice you just cannot hit every possible access
> point of the (rich, in our case) API so the tests pass too often.
>
> Which is why we relentlessly test against reverse-depends to _at least ensure
> buildability_ from our releases.
>
> As for seamless binary upgrade, I don't think in can work in practice.  Ask
> Uwe one day we he rebuilds everything every time on Windows. And for what it
> is worth, we essentially do the same in Debian.
>
> Sometimes you just need to rebuild.  That may be the price of admission for
> using the convenience of rich C++ interfaces.
>

Okay, so would you say that Kirill's suggestion is not overkill?  Every 
time package B uses LinkingTo: A, R should assume it needs to rebuild B 
when A is updated?

Duncan Murdoch



[Rd] Upgrading a package to which other packages are LinkingTo
Duncan Murdoch