New Gash build Bash without Bash, Coreutils, and a few others

[Timothy Sample]

Hi Guix,

Here’s an update about bootstrapping for you.

I am very pleased to announce that Gash (having absorbed Geesh) is now
capable of building Bash without Bash, Coreutils, Grep, Sed, or Tar.
That is, Gash provides alternatives, written in Scheme, to all the
utilities needed by the “gnu-build-system” that are normally provided by
those packages.  Note, however, that this work is still very much at the
“proof of concept” level.

This is exciting because it means that we are within sight of removing
each of those packages from the set of bootstrap binaries (in the
context Jan’s work on MES and the Guix “reduced binary seed bootstrap”).
AIUI, that means that, besides Guile and MES, the set of bootstrap
binaries need only contain AWK, Patch, Bzip2, Gzip, and XZ.

There is still a lot to do.  Concretely, Gash itself has to be
bootstrapped.  There is some mildly bit-rotten code for this that will
have to be revived.  Gash should also be ported to Guile 2.0, since that
is the current bootstrap Guile, and it would be nice not to change it.
(This shouldn’t be too hard.)

As for the other utilities, I don’t really have a strategy for them.  I
would imagine that writing a good-enough “patch.scm” would not be too
hard.  AWK is difficult, but after spending (way too much) time reading
“configure” scripts, I think it could be avoided.

You can see the latest code at <https://gitlab.com/samplet/geesh> (yes,
the URL needs an update).  The work described in this message is on the
“wip-bootstrap” branch.


-- Tim