Is it possible to load multiple versions of the same system?

[Faré]

> Curiosity about a general
> solution is what prompted this thread,

Oh well, I'm not going to expect much to come out of it, then.

> With respect to package renaming, I've asked Michał Herda to comment on
> whatever issues he'd had with "destructive package renaming" [1].  I
> understand it as referring to the state-based global-reader implementation
> of packages, which seems to entail well known problems like reentrancy and
> readtable leakage.
>
No, I use rename-package, but I leave it as the programmer's
responsibility to ensure that a package's canonical name while
compiling a fasl will be a valid name for the correct package at load
time. In the general case, this might entail instrumentation or
shadowing of defpackage and make-package. No reader hack necessary.

> [The XCVB] approach sounds like one motivated by version conflict between the
> build system and system being built.  Is that correct?
>
Yes. Having lots of dependencies means that "interesting" things may
happen if you start compiling an incompatible version of a library
you're using. Or even a compatible version that resets important data
structures in one file that will only be filled in in another.

> I wasn't really thinking about that, but now that I am I'm reminded of
> various parts of your paper [2].  The bootstrapping, upgrading, and
> distribution of ASDF seems very thorny indeed.
>
> [2]: http://fare.tunes.org/files/asdf3/asdf3-2014.html
>
Indeed. Thanks for being a good public.

—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org
A president worth voting for wouldn't run for office.