
 How to build this version of s6-overlay:

 - look at the variables in conf/defaults.mk. Do not
modify defaults.mk itself, but those variables are the ones
you can pass to make for configuration.

 - look at the first column of conf/toolchains. These are
the valid values for ARCH. More may be added later. The
second column is an opaque tag for the downloaded toolchain
giving the flavour of the arch. For instance, the
aarch64-linux-musl toolchain is called "pi4" and will build
binaries for a Raspberry Pi 4.

 - invoke make with the OUTPUT, ARCH, DL_CMD etc. that you want.
Do not hesitate to -j8 if you have a big machine. Or to -j128
if you have a REALLY big machine.

 - When it's done, there's a lot of stuff in the output directory. 
The ultimate targets are:

   * s6-overlay-${ARCH}.tar.xz: the tarball containing
all the skaware binaries for ${ARCH}, all nice and static. It
should be used by everyone who does not use a distro that provides
the same binaries.

   * s6-overlay-symlinks-arch.tar.xz: the tarball
containing /usr/bin symlinks to those binaries. It should normally
not be used. It MUST NOT be used by distros providing binaries in
/usr/bin. The only people who want this are the ones who want to
manually call skaware binaries without putting /command in their PATH.
The tarball is called "arch" because the symlinks point to the
programs in the arch-dependent package; but since they're only
symlinks, this tarball itself is not arch-dependent.

   * s6-overlay-noarch.tar.xz: this tarball contains
s6-overlay itself, i.e. the set of scripts and files that allow a
container to run under s6. Everyone who wants to run s6-overlay
must install this.

   * s6-overlay-symlinks-noarch.tar.xz: this tarball
contains /usr/bin symlinks to the few scripts provided by s6-overlay.
The overlay itself will run without it, but if users have stuff
like "/usr/bin/printcontenv" hardcoded in their scripts, these
symlinks will help them. Distros that provide skaware binaries
themselves (and do not use slashpackage) will almost certainly
want to install this.

  * syslogd-overlay-noarch.tar.xz: this tarball
contains scripts to run a syslogd emulation at container boot
time. It basically replaces socklog-overlay. (The socklog binary
itself isn't needed anymore since s6 provides a similar utility.)
Users who install this will have a syslogd service in their
container, logging to subdirs of /var/log/syslogd.
