Hello!
In some cases, it’s useful to be able to pin a particular Guix version
and to use that version (see the RepPar paper for some examples.)
A naive way to do that is:
git clone …/guix.git my-pinned-guix
(cd my-pinned-guix; git checkout deadbeef)
guix package -L my-pinned-guix --manifest=my-manifest.scm
However, this is currently broken for several reasons:
1. ‘fold-packages’ recursively traverses ‘my-pinned-guix’ for .scm
files, and on its way it finds build-aux/build-self.scm,
tests/*.scm, and emacs/*.scm, which breaks it all. These
directories have to be explicitly removed before we can do
something.
Internally, ‘%package-module-path’ can have entries that are pairs
and where the cdr restricts the search of .scm files to a
sub-directory. We should expose that facility to -L and
‘GUIX_PACKAGE_PATH’ using some special syntax.
That way, one could do (say):
guix package -L my-pinned-guix,gnu/packages
meaning that only the ‘gnu/packages’ sub-directory is searched.
OTOH, it may be advisable to use the (guix …) modules from
‘my-pinned-guix’ and not just the (gnu packages …) modules, because
the former obviously contribute to the final result.
2. The ‘gnu/packages/patches’ sub-directory is not automatically added
to the search path, so in fact one has to run:
guix package -L my-pinned-guix \
-L my-pinned-guix/gnu/packages/patches …
so that patches are found. Not convenient.
3. When doing so, we get loads of:
;;; note: source file /tmp/guix/guix/build/perl-build-system.scm
;;; newer than compiled
/home/ludo/src/guix/guix/build/perl-build-system.go
We should silence Guile.
4. Related to #1: since everything is evaluated, this is ~10 times
slower than the normal thing.
I think ‘guix pull’ would be a good place to add support for tagging
Guixes and similar, but it would be good if the naive approach above
would work just as well.
Ludo’.
