I've finally moved away from LC_MESSAGES=C on my main
development system half a year ago and finally spotted
that a grep for "Stop\.$" stopped to yield anything now.

It appears that manually specified IMAGEDIR, e.g. by adding

  IMAGEDIR = ~/out/$(shell date +%Y%m%d)

to ~/.mkimage/profiles.mk, might be problematic due to
missing globbing.  Let's make sure the paths are globbed
and directories are created -- since make's wildcard()
returns an empty string when there's nothing there [yet].

This time it's

  xorriso : FAILURE : -volid: Text too long (33 > 32)

and todo-- as well.

Somewhat kludgy unfortunately and might need even more tweaking,
I have only armv7l board handy at the moment to verify that
the transformation is going to work.

QEMU is bailing out here and now ("Exec format error").

Example sources.list.sisyphus.armh of the season:

  rpm http://ftp.altlinux.ru/pub/people/asdus/sisyphus armh classic
  rpm http://ftp.altlinux.ru/pub/people/asdus/sisyphus noarch classic

mkimage and hasher can make use of qemu to run
non-native binaries while working on the chroots;
thanks kas@, manowar@ and sbolshakov@ for implementing
this functionality as well as providing nice examples
through mkimage-profiles-arm and mkimage-profile-armrootfs.

This required the architecture check to be added since baking
a tarball with "arm" as its specified arch and x86_64 inside
isn't particularly good thing to let slip through; however
the implementation is quite fragile, bugreports and patches
are seriously welcome.

NB: APTCONF evaluation order between lazy make and nimble shell
turned out to be quite a delicate issue in this particular case.

The only thing to be fixed was setarch(8) symlinks assumption
that is correct for x86 but not for ARM.

There's also some hasher(7) setup to be done:

  mkdir -p ~/.hasher
  echo >> ~/.hasher/config <<-EOF
  def_target=arm
  #cache_dir=$HOME/tmp	# depends on RAM/storage configuration
  EOF

...and of course apt(8) should be properly set up too.

An example PoC build on a CM-A510 board (tmpfs):

  $ make BRANDING=altlinux-centaurus ve/bare.tar.gz
  ** ARCH: arm
  18:10:45 initializing BUILDDIR: build/
  18:10:45 preparing distro config: build/distcfg.mk
  18:10:46 starting image build: tail -f build/build.log
  18:14:49 done (4:02)
  ** image: $TMP/out/bare-20120706-arm.tar.gz [23M]

Allow to put the log files and reports in a custom directory instead
of IMIGEDIR.

It's hard to tell a successful build from a failed one
if downstream hides the exit code; it's useless to continue
a `for' loop if a pipe shoves that to a subshell; well it seems
that a bashism is worth a thousand quirks with extra fds here.
Minor regexp enhancements are also due.

reports.mk made a bit more resilient/prudent either.

A pretty common issue breaking the image build is inter-package
file conflict resulting in hsh-install failure down there.
Let's bring that back to attention conveniently.

The purpose is being able to examine particular target interdependency
graph for a given image having been configured to avoid convoluted
dependencies (loops in particular).

The implementation is based on SHELL hook hint by John Graham-Cumming:
http://cmcrossroads.com/ask-mr-make/6535-tracing-rule-execution-in-gnu-make

It was briefly mentioned in QUICKSTART but somehow managed
to evade the commandlines provided.  And while at it, let's
make errors like this more explicit to avoid extra lookups.
Oh, and fix QUICKSTART so that readers miss the hassle. :)

Thanks Vladimir Karpinsky for pointing this problem out.

The former toplevel Makefile is now toplevel main.mk;
this change allows for multi-target, multi-arch processing
in the current toplevel Makefile.

As the "build" symlink semantics change quite considerably
when one is doing bulk builds (several pruned builddirs might
be useful for comparison), BUILDDIR is now much more likely
to be recreated: the cases when it will persist are when it's
either a single-image build or when the prefix hasn't changed.

There are some more or less subtle bugfixes and enhancements
all over the map as well.

Done within 20111230..20120102 timeframe, actually...

$(SHORTEN) is better in the midst of the pipe
so that greps are terminal and can sense the tty
(or the lack thereof in case we're logging further).

The idea is to check:
- the reachability of every target
  used to build the image in question;
- the availability of all the package lists
  and subsequently packages for that image;
- the lack of "dangling" intermediate targets,
  features, pkglists, hooks etc.

So far only the first step is implemented --
it's easy and somewhat helpful already for
  make CHECK=1 all

As was (quite reasonably) asked by someone and me too,
why should a successful build yield a *red* line
(a grep's default)?

So now it's new and improved, 25% free and so forth:
with a successful build you get a green line, while
errors from a broke one result in red ones.

Clinically tested in both b/w and w/b colour schemes;
in case you're not satisfied, please return original
ANSI_OK and ANSI_FAIL values to the colour dealer
and pass your favourite ones instead.

Essentially some more polishing:
- image path extracted from downstream build log;
- extended error/warning regexp a bit so those with
  color grep options get even prettier output.

Notes:
- "1024" a magic number (briefly explained when introduced)
  moved to a sort of variable;
- "100 lines" for tail(1) is a rule-of-thumb taking into account
  typical amount of hasher/mkimage exhaust given GLOBAL_VERBOSE.

This one regulates the build wrapper: if the value is non-empty
then nice(1) and ionice(1) will be attempted so that the build
behaves better in regard to other tasks running on the system.

A few doc/variables.txt updates along the way.

Thanks torabora@ for yet again seemingly obvious feature request
which strangely managed to evade implementation before.

On an afterthought, mass builds would suggest too much coffee
instead of a progress indicator -- so implemented the latter.

NB: the actual downstream-make-calling rule would expand the "naive"
$(shell date) too early: the rule is evaluated before starting its
execution, and as it's the time consuming one the shell evaluation
was in need, not make's.  The result is less generally available
(needs to be double quoted and won't work inside e.g. awk programs)
but way more precise.

Implemented opportunistic alarm support as proposed by torabora;
the actual result depends on readline and/or terminal settings
(read up on "visual bell" vs "audible bell" in case it's wrong).

TODO: this ought to be shifted downstream when proper logging
framework is there.

This is quite a large-scale change since mkimage-profiles got used to
baking distributions over the last year, and virtual environments are
quite different, so e.g. image.in/Makefile had to be split in two with
the main part of it moved into features.in/iso/lib/.

Short overview:

- features.in/Makefile: lib/ support
  (supporting VE images requires dynamic modifications
  to image.in/Makefile before starting the build;
  the most natural way to achieve that seems to use
  features mechanism along with makefile include dir)

- packaging format related part moved into features.in/pack
  (should be better prepared for diversity either)
- features.in/iso renamed to features.in/build-distro
- features.in/ve  renamed to features.in/build-ve
  + NB: these could not be merged as e.g. features.in/build
    due to completely different script hooks

- lib/image.mk renamed to lib/build.mk
- image, config, log postprocessing moved downstream
- added a sort of a topping in the form of lib/sugar.mk
- assorted style fixups (like ifeq usage)

- clean.mk: reliability fix (the problem was observed by Oleg Ivanov
  and me too but finally it did get the attention quantum)

- reviewed, updated and extended docs
  + QUICKSTART: should be[come] a step-by-step guide
    (thanks Leo-sp50 for prodiving feedback)

Just in case the build.log will be inobvious, and it's easy to diagnose
automatically.  Thanks Andrey Stroganov for this use case.

Thanks for improving the initial implementation go to raorn@ for kind
commit lynch and to Yuri Bushmelev for actually suggesting something
more concise.

BTW the "1024" magic number was taken out of thin air:
the "no free space" errors are most likely to happen while
forming/populating a chroot (apt/rpm errors out) and chroots are
roughly two orders of magnitude heftier than a megabyte.

In particular:
- .base is now generated from pieces (see image.in/Makefile)
- s/DISTROS/IMAGES/g; s/CONFIGS/DISTROS/g (for clarity)
- s/DISK_LISTS/MAIN_LISTS/g ("disk" was early m-p-d legacy)
- introduced BASE_PACKAGES to complement BASE_LISTS
- minor tweaks to Makefile (ARCH and DATE moved elsewhere)
- libdistro.mk: dropped overlooked IMAGE_INIT_LIST copy
- clean.mk: silly cleanup

Thanks go to lakostis@ (see #18047) for all the aic94xx reminders
and the final testing of the proposed image.

...and some more cosmetic fixes

- image.in/functions.mk: rework kpackage()
  + it takes two arguments explicitly now: this adds some noise
    for "generic" invocations but is rather less messy with recently
    introduced STAGE1_KFLAVOUR (which in its turn is rather cleaner
    than messing with KFLAVOURS, especially since soemthing changed
    in presumably apt and we can't rely on kernel packages being
    installed in the order formed).
- BUILDDIR/DEBUG related fixes
  + Makefile: BUILDDIR initialization moved to distro.mk
- build.log += git info

Now we don't dump all the gory details onto thee
but rather log them handsomely and present only
the most important details by default; use DEBUG=1
and/or BUILDLOG=/path/to/file to tweak.

Also introduced IMAGEDIR and IMAGENAME.

The rest:
- ovz-smp is no more
- base-l10n pkglist (suggested by Alexander Kuprin)
- clean.mk:
  + fixed an oversight: the test result erroneously applied
    only to the first command of several ones that should be
    run iff build/ is a symlink
  + drop implicit rules (it's no C code)
- Makefile: more reasonable iso names
- image.in/Makefile: .disk/date too

- more thorough build stages inline doc
- quieter BUILDDIR instantiation
- branding-altlinux-sisyphus by default
- prettify installer selection somewhat
- mkimage #24669 fixed upstream
- sub.in/stage1/modules: +drm (as in m-p-d, for KMS)
- tags2lists: generalize a bit

A major change in approach largely thanks to discussions
with Alexey Cheusov but also well aligned with my own findings:
autoconf doesn't let the variables to form an inheritance.

And data flow described at http://www.altlinux.org/WhiteLabel
(which in its turn was born thanks to Gavin Henrick of Diva Telecom
and to Alexander Bokovoy of SaM-Solutions) is really dependent on
the existence of such an inheritance.

Also:
- distro.mk += try()
- "hide" special targets
- fixed wrt distro/.{base,init,metaconf}, thx gns@
- README updates
  + added metaconf.mk
  + clarifications
- updated pci.ids location for hdt

- get rid of $dest
- work on features.in/syslinux
- README++

It wasn't serving any good by now...
README++ and cleanups all over the place

- set(), add(), log()
  + special thanks to rider@ for log format feedback
- simple debug facility
- builds, installs and runs... again

- syslinux: menu.c32 works
- features: initial draft
  + memtest
- mv pkg/ pkg.in/
  + server-base: include openssh-blacklist by default
- mv isodata/ copy/
- README: changed to utf8, added an URL

Building m-p-d stuff in-tree was plagued by accidental
generated file commits, and it wasn't nice at all anyways.

As not every package list is useful for every distro,
only the needed lists should be copied for a particular one.

- s/stage2/install2/g
- added pkg/lists
- initial README (ru_RU.KOI8-R)
- mkimage topdir is in image.in/, really (off-tree build)
  + initial bin/mktmpdir
  + BUILDDIR (works)
- s/cd/iso/
- drop --with-distro (considered harmful)

Initial profile lacking any real stuff but presenting the idea;
autoconf-based like m-p-d.