Re: Bug#793067: Bug#792328: info: can no longer find the Emacs manual

[Eli Zaretskii]

> Date: Mon, 3 Aug 2015 21:27:32 +0100
> From: Gavin Smith <address@hidden>
> Cc: Rob Browning <address@hidden>, address@hidden, 
>       Texinfo <address@hidden>
> 
> > I don't see how this would solve the issue at hand.  Installation of a
> > manual is a system-wide action, whereas Rob wanted a way for a _user_
> > to specify her preferred version(s) of the manual(s) to use at any
> > given moment.
> 
> How the user accesses manuals of course depends on how the manuals
> were installed.

The issue, as I understand it, is how the user tells the Info reader
which manual from those installed she wants to read, when there are
multiple versions of the same manual installed.

> Where my suggestion fails is inter-manual references.

But that's the hard issue to solve.  All the others are already solved
more or less satisfactorily.

> It would still be better than what we have at the moment, though.

In what way would it be better?  I don't see any significant
improvement, just the added complexity.

> As I remember saying before, I don't think we need to be any more
> sophisticated than what the shell does when it is trying to find an
> executable program.

We already have everything that the shell has: INFOPATH is our
equivalent of PATH, and we can use links and file renaming like people
do with shell commands.  So if all we want is to provide the same
features as the shell, we already provide them.

> If the shell can avoid a lot of complexity handling multiple
> versions of programs, I suspect it may not be necessary for
> documentation either.

The shell doesn't have the problem of referencing other commands under
user control about which version is being referenced.  If a command
'foo' invokes command 'bar', then the first 'bar' found on PATH will
be invoked, even if 'foo' is a versioned file named 'prog-1.2.3'.

The equivalent works with, say, GCC, because GCC has all of its
auxiliary programs and files in a versioned directory, whose name is
dynamically computed by GCC given its own version that is hard-coded
into the binary, so the only file that needs to be renamed is the GCC
executable itself.  But this has its limits: e.g., if I have more than
one version of Binutils installed, GCC will always invoke the 'ld'
executable it finds first on PATH, not some 'ld-X.Y.Z' that I happen
to want to use.

IOW, the equivalent of the problem of inter-manual references exists
in shell commands as well, and is not solved well there, either.