[ANNOUNCEMENT] Restructuring the automake and autoconf packages

Corinna Vinschen vinschen@redhat.com
Mon Dec 3 10:28:00 GMT 2001

This message is VERY important.  PLEASE read the whole thing --
it will save everyone a lot of time and a lot of FAQs.

  What, Why, How, Who, Where, When, and Installation

(1) automake has been replaced by three separate packages
      automake  (*)
(2) autoconf has also been replaced by three separate packages
      autoconf  (*)
(*) These are NOT the real autotools.  These are wrapper
scripts.  Since the auto*-stable packages install into
/usr/autotool/stable/, and the auto*-devel packages install
into /usr/autotool/devel/, the wrappers sit in /usr/bin, and
redirect to the appropriate version, based on the
AC_PREREQ(version) statement in the target project's

(1) There are incompatibilities between
      autoconf-2.13 and autoconf-2.5x
      automake-1.4  and automake-1.5
and most (cygwin-external) projects have been slow and/or
resistant to migrate to the newer versions.

(2) cygwin should not "push the envelope" and try to force
non-cygwin developers and projects to adopt the new autotools
(or try to coerce external projects to stay with the old
autotools for our sake)  [Thus spake cgf]  In other words,
cygwin's earlier move to autoconf-2.52 and automake-1.5, without
providing some sort of backward compatibility, was ill-advised.

(3) autoconf/automake/libtool must all share the same prefix
(usr or usr/local or...) because they each access each other's
m4 macros (underneath <prefix>/share/).

(4) the newest version of libtool (not even in CVS yet) that
transparently supports dll-building on cygwin requires the
NEW versions of autoconf/automake.  If we want a cygwin-friendly
libtool, we NEED the new versions.  Currently, this libtool is
only available here at the following link -- but rest assured,
we want to get this into the official distribution soon.
(The pre"compiled" version at that website won't work with these
new auto* packages -- it is a vestige of earlier experiments.
However, you should be able to download the "source" version from
the same site and build it)

(5) Since the new versions of autotools are NOT completely backward
compatible with the old versions, we -- the cygwin community -- are
left with four choices:
  a) provide both autoconf-2.13 and -2.52, and both automake-1.4p5
     and -1.5
  b) immediately fork every package we distribute, fix 'em so that
     they all work with the new autotools -- AND then convince their
     upstream maintainers to accept these changes.  This contradicts
     point (2) above.
  c) do NOT support the new versions at all. Stay with the old
     versions -- but then we won't get the spiffy new transparent
     dll-supporting libtool.
  d) okay, developers: you can't work with the autostuff of packages
     that require the OTHER autoconf/make.  Sorry.  (Okay, you could
     use setup to uninstall/reinstall and switch between the two
     versions).  Or cygwin-developer1 can promise to stay with the
     old autotools -- and he can be in charge of "stuck-in-the-past"
     packages, and cygwin-developer2 can track the new tools-- and she
     can be in charge of "progressive" packages...

Option (b) is ruled out by point (2) above.  Option (c) will probably
work NOW with most packages -- but we'll be left behind when the
upstream maintainers eventually DO update to the new versions of
autotools (it WILL happen eventally).  Plus, we lose the spiffy libtool
(see point (3) above).  Option (d) is just plain silly.  Option (a) --
provide both new and old versions of autotools and somehow convince them
to play nicely together -- is the only real choice we (the cygwin
community) have.

(6) Sociological issues.  For MANY years, the autotools remained
backward compatible with each new release, until 21 May 2001,
the advent of autoconf-2.50.  The autoconf developers decided that
the benefits of breaking backward compatibility outweighed the harm.
Actually, they had gone *as far as they could go* with the 2.13
structure.  Since autoconf (and the whole autotools suite) is the
backbone -- not counting gcc -- of most cross-platform open source
packages, this incompatibility is going to cause a massive ripple
effect.  We (the open source community) are entering a phase where
some packages will AC_PREREQ(2.50) -- but others will delay the
transition and will remain at AC_PREREQ(2.13) or earlier.

This means that Joe Developer can't update his local autotools to
the new version, unless all of the packages he works on are ALSO
updated -- but any given project can't update until most of its
developers EACH update their own local autotool installation.  This
gives you a huge web of interlocking dependency, leading to statis:
gridlock.  The only way to fix this problem -- in an open source
community global way -- is for distribution maintainers, such as
Red Hat, Debian, (and cygwin), to make it easy and automatic to have
BOTH a stable and a development version of the autotools installed.

Debian has done some work toward that end, by providing wrapper
scripts that autosense the target project's desired version, and then
manipulating symbolic links to point to the correct version.  However,
this is not multi-user safe.

The *right* answer here is for the autotools people to take charge --
but they've focused on making it easy to migrate a package from old to
new (lots of work in 'autoupdate'), rather than making it easy for two
versions to coexist.  In other words, they have focused on the
technical issues, rather than the sociological ones (and that's not
a bad thing).  For now (and the future) I think a wrapper-script
solution will be necessary -- on all platforms.  But let's make things
work on cygwin, first -- we have a compelling need, in the new libtool

So, to sum up: Why all this fuss?  Because we have a need for both
the "old" versions of autotools and the cutting edge versions to
coexist.  We need the old versions in order to work with existing
packages that have not yet taken the plunge and converted to the
newer versions.  But, we need the newer versions because the SOME
packages HAVE taken the plunge, AND the new super-special
dll-supporting libtool won't work with the older autotools.

are the packages installed?

autoconf-2.13 and automake-1.4-p5 are built and installed into
/usr/autotool/stable/[bin,share,...].  These are packaged
in cygwin-setup compatible form under the names:
Of course, you also get
As stated earlier, everything else goes under

autoconf-2.52 and automake-1.5 are built and installed into
/usr/autotool/devel/[bin,share,...].  These are packaged
in cygwin-setup compatible form under the names:
In addition to the "text" documentation, these development
packages install their info files and man pages under the
"real" /usr/info and /usr/man/ trees, so you needn't set your
MANPATH or INFOPATH variables.  So, under the main /usr/ tree:
As stated earlier, everything else goes under

So, we now have both stable and development versions of autotools
installed -- but we can't use them, because
/usr/autotool/stable/bin and /usr/autotool/devel/bin aren't likely
to be in your PATH.  That brings us to

autoconf-scripts-2.52 and automake-scripts-1.5a, from
http://www.neuro.gatech.edu/users/cwilson/auto-wrappers/.  These
are built and installed under /usr/[bin,doc,...] and are packaged
in cygwin-setup compatible form as:
And again, you also get
Of course, the natural question is,
  "Why is this new 'autoconf-scripts' thing packaged as 'autoconf'?
   Ditto 'automake-scripts'?  Isn't that really confusing?"
The answer is
  "To help setup update everyone's system properly.  With the
   current setup.exe, it seems to be difficult to "cleanly"
   obsolete a package -- witness the trauma when the 'xpm'
   package was removed and the 'xpm-nox' package was added.
   Besides, the /usr/doc/Cygwin/auto*.README files explain
   everything. </famous last words>"

Final note: these packages all passed their own internal tests
with flying colors, assuming the new 'mktemp' package is installed.
  autoconf-2.13  : expected passes 226 unexpected failures 33 (*)
  autoconf-2.52  : All 155 tests successfull
  automake-1.4p5 : All 195 tests passed
  automake-1.5   : All 323 tests passed
(*) This is the same performance as the old autoconf-2.13 package
from four months ago.

do the packages work?

Well, the autotools themselves are just magic.<g>  But I can
explain how the wrapper scripts work.  There is a wrapper
script that corresponds to (and is named the same as) every
"real" autotools program.  The wrapper accepts all of the
same options that the real "stable" and "development" versions
of the target program accept.  The wrapper parses those objects,
and will call the target program with the same argument list
that it received.

Each wrapper script looks in the directory from which it was
called for a 'configure.in' or 'configure.ac' script, and parses
that file looking for the AC_PREREQ(version) command.  If
version <= 2.13, then the wrapper will call the stable target.  If
version > 2.13, or if there is no AC_PREREQ() statement, then
the development target is called.  The wrappers use the autoconf
version to determine which target to call -- even when the wrapper
is for an automake program like 'aclocal' or 'automake'.  The
reason?  It's easier that way -- and the compatibility issues
between automake-1.4-p5 and automake-1.5 are much less severe
than those between autoconf-2.13 and autoconf-2.52.  In other
words, it matters less if we call the "wrong" target for automake.

However, the wrappers don't just exec the appropriate target.  They
also set the PATH variable and the M4PATH variables and export them.
That way subsequent calls to other autotools will go DIRECTLY to
the appropriate target, without running the wrappers.  For instance,
if you run 'autoreconf', then the autoreconf wrapper will determine
(say) that you need the development version.  So, it sets the PATH
to /usr/autotool/devel/bin:${PATH} (and similarly for M4PATH).  THEN
it calls the "real" (devel) autoreconf.  But the "real" (devel)
autoreconf itself will call autoconf and aclocal and autoheader...but
since the PATH has already been set, it will directly call the
"real" (devel) versions, not the wrappers.

Finally, there's one or two other little things.  First, the scripts
do not have '/usr/autotool/devel/' and '/usr/autotool/stable/'
hardcoded into them -- although the scripts default to using those
prefixes for the stable and development versions.  However, you can
install your own versions of the "real" autotools into /bob/stable/
and /cindy/devel/, if you like.  Just set (and EXPORT!!!) the
environment variables "AUTO_STABLE" and "AUTO_DEVEL":
  $ export AUTO_STABLE=/bob/stable
  $ export AUTO_DEVEL=/cindy/devel

Second, many NON-autotools packages install m4 scripts to assist
the autotools.  Gettext is one such package: it puts the following
files in /usr/share/aclocal/  (NOT into /usr/autotool/devel/share/aclocal
nor into /usr/autotool/stable/share/aclocal):
BUT the autotools will NOT look there without help -- being
preoccupied as it were with their own
/usr/autotool/[stable|devel]/share/aclocal directory.  So, the
automake-stable cygwin package and the automake-devel cygwin package
have been modified to look not only in
  /usr/autotool/stable/share/aclocal (for automake-stable)
  /usr/autotool/devel/share/aclocal  (for automake-devel)
but they ALSO parse the file
  /usr/autotool/stable/share/aclocal/dirlist (for automake-stable)
  /usr/autotool/devel/share/aclocal/dirlist  (for automake-devel)
for additional directories to search -- BEFORE their own aclocal.
In the current releases, dirlist contains only
Thus, 'aclocal' -- which is the only autotool affected by the
"added .m4 file" problem -- will use the following search path:
when looking for .m4 files.

Lastly, if you want to FORCE the use of the stable or development
version of the autotools, nothing could be simpler.  Just
  $ export PATH=/usr/autotool/stable/bin:${PATH}
  $ export M4PATH=/usr/autotool/stable/share/autoconf
for autoconf programs.  Or
  $ export PATH=/usr/autotool/stable/bin:${PATH}
  $ export M4PATH=/usr/autotool/stable/share/aclocal:\
for automake programs.  Then just call your autotool.

Charles Wilson wrote the autoconf-scripts (wrapper) package
and the automake-scripts (wrapper) package.  He also packaged
the initial release of the the new autoconf-stable,
autoconf-devel, automake-stable, automake-devel,
autoconf (wrapper) and automake (wrapper) packages.  However;

Corinna Vinschen is the maintainer of the autotools packages.

But ALL communication regarding these tools on cygwin, and the
new wrappers and packaging, should go to cygwin@cygwin.com

Thanks also to Earnie Boyd, Chris Faylor, and Robert Collins
for helpful ideas and feedback on the list.

At your friendly neighborhood cygwin mirror.

Note that downloads from sources.redhat.com (aka cygwin.com) aren't
allowed due to bandwidth limitations.  This means that you will need
to find a mirror which has this update.

In the US, ftp://mirrors.rcn.net/mirrors/sources.redhat.com/cygwin/
is a reliable high bandwidth connection.

In Japan, ftp://ftp.u-aizu.ac.jp/pub/gnu/gnu-win32/ is already

In DK, http://mirrors.sunsite.dk/cygwin/ is usually up-to-date.

If one of the above doesn't have the latest version of this package
you can either wait for the site to be updated or find another

As soon as the new versions propagate to the mirrors.  (okay, this
was just an excuse to get all six "reporter's" questions in here:
who, what, why, when, where, how)

To update your installation, click on the "Install Cygwin now" link
on the http://cygwin.com/ web page.  This downloads setup.exe to
your system.  Save it and run setup, answer the questions and pick
  'autoconf'        from the 'Devel' category.
  'autoconf-stable' from the 'Devel' category.
  'autoconf-devel'  from the 'Devel' category.
  'automake'        from the 'Devel' category.
  'automake-stable' from the 'Devel' category.
  'automake-devel'  from the 'Devel' category.
You may need to click on the "Full" button if the new packages
(*-devel, *-stable) do not appear.

Final Note:  You made it!!!! You read this whole message!!!
Congratulations -- now there are just six more messages to go. :-)

Actually, there will be six 'pro-forma' announcements, for each of
the new and updated packages.  But each will just refer back to this
message for the real "meat".

Chuck Wilson
Corinna Vinschen


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