Re: m4-1.4.4b problems

[Ralf Wildenhues]

A tiny bit of clarification:

* Eric Blake wrote on Thu, Jun 22, 2006 at 03:27:07PM CEST:
> According to Bruno Haible on 6/22/2006 5:45 AM:
> > 
> > I got two problems with m4-1.4.4b:
> > 
> > 1) After installing it, automake breaks like this:
> > 
> > $ automake-1.9 --gnits  tests/Makefile
> > NONE:0: /packages/gnu/bin/m4: `m4_symbols' from frozen file not found in 
> > builtin table!
> > autom4te: /packages/gnu/bin/m4 failed with exit status: 1
> > automake-1.9: autoconf failed with exit status: 1
> > make: *** [Makefile.in] Fehler 1

Ouch.

> > I had m4-1.4o installed at the same place earlier.
> 
> m4-1.4<letter> is a beta release, which will be the eventual m4-2.0.
> There are some known incompatibilities in the frozen file format added in
> format version 2, that m4 1.4.x is documented to be unable to understand
> (since it only parses format version 1).  In short, downgrading m4
> potentially invalidates all frozen files created with the newer version.
> Ralf Wildenhues already identified frozen file format incompatibilities as
> an issue for autoconf,

Right: there are incompatibilities between M4-1.4.3 and current CVS M4.

> and added a patch to CVS autoconf that melts all files when
> bootstrapping autoconf

This is not entirely correct.  I added a minimal patch that avoids using
_installed_ frozen files when creating $top_builddir/bin/autoconf.in.
We still do not use --melt for any other built files in Autoconf, since
as far as I can see we create the respective uninstalled frozen files
before using them.

> (in other words, avoids using frozen files leftover from previous
> runs, in case the bootstrap picks up on a new m4 version),

This is only true for installed files.  You may have to issue a `make
clean' after upgrading M4.  Or simply throw away your build tree.

Cheers,
Ralf