Hi,
Extension is a mechanism which allows to have more CLI subcommands. For
example, see guix-modules or gwl; they extend Guix by providing the
subcommands “guix module” or “guix workflow”. Note that:
- guix-modules uses guile-build-system and is one file.
- gwl uses gnu-build-system and is multi-files
I would like to have multi-files but without the “complexity” of gwl
(transform .scm.in to .scm at build time, etc.).
Let take an example. The structure is fixed and it looks like:
--8<---------------cut here---------------start------------->8---
$ tree /tmp/example/
/tmp/example/
├── guix
│ └── extensions
│ └── hello.scm
└── my
├── module
│ └── sub.scm
└── top.scm
4 directories, 3 files
--8<---------------cut here---------------end--------------->8---
Then setting GUIX_EXTENSIONS_PATH just works.
--8<---------------cut here---------------start------------->8---
$ GUIX_EXTENSIONS_PATH=/tmp/example/guix/extensions guix help
Usage: guix OPTION | COMMAND ARGS...
[...]
plumbing commands
[...]
hello hello world
Report bugs to: bug-g...@gnu.org.
GNU Guix home page: <https://guix.gnu.org>
General help using Guix and GNU software: <https://guix.gnu.org/en/help/>
--8<---------------cut here---------------end--------------->8---
So far, so good!
What is my issue? :-) Well, my issue is to correctly set the load path
so that I can use the module defined under the folder my/.
For instance, this ’hello’ extension reads:
--8<---------------cut here---------------start------------->8---
$ GUIX_EXTENSIONS_PATH=/tmp/example/guix/extensions guix hello
hello
path: "/tmp/example/my"
load-path:
"/tmp/example/my"
"/gnu/store/qdhi0a69908b0521gqzxdsf9a9bniqxi-guix-module-union/share/guile/site/3.0"
"/gnu/store/1jgcbdzx2ss6xv59w55g3kr3x4935dfb-guile-3.0.8/share/guile/3.0"
"/gnu/store/1jgcbdzx2ss6xv59w55g3kr3x4935dfb-guile-3.0.8/share/guile/3.0"
"/gnu/store/1jgcbdzx2ss6xv59w55g3kr3x4935dfb-guile-3.0.8/share/guile/site/3.0"
"/gnu/store/1jgcbdzx2ss6xv59w55g3kr3x4935dfb-guile-3.0.8/share/guile/site"
"/gnu/store/1jgcbdzx2ss6xv59w55g3kr3x4935dfb-guile-3.0.8/share/guile"
"/home/simon/.guix-profile/share/guile/site/3.0"
"/home/simon/.config/guix/profiles/emacs/emacs/share/guile/site/3.0"
"/home/simon/.guix-profile/share/guile/site/3.0"
"/home/simon/.config/guix/profiles/emacs/emacs/share/guile/site/3.0"
"top": "/tmp/example/my/top.scm"
"sub": #f
"module/sub": "/tmp/example/my/module/sub.scm"
--8<---------------cut here---------------end--------------->8---
which means that %load-path contains ’my’ module and ’%search-load-path’
finds the relevant files. See plain script below.
However, how do I use the exported procedure in these files my/top.scm
and my/module/sub.scm? For instance, my/top.scm reads:
--8<---------------cut here---------------start------------->8---
(define-module (my top)
#:export (from-top))
(define (from-top)
(let ((here (current-filename)))
(format #t "top: ~s~%"
(string-append (dirname here) here))))
--8<---------------cut here---------------end--------------->8---
but then I miss how to use ’from-top’ inside
’guix/extensions/hello.scm’. Obviously ’#:use-module (my top)’ cannot
work because the load path is extended by the script itself.
I have tried
(apply (@ (my top) from-top))
or
(apply (@@ (my top) from-top))
without success. Well, I get:
ERROR: In procedure %resolve-variable:
How can I write a multi-files extension?
Cheers,
simon
guix/extensions/hello.scm:
(define-module (guix extensions hello)
#:use-module ((guix scripts)) ;define-command, category, synopsis, etc.
;;#:use-module (my module world)
#:export (guix-hello))
(define (my-path)
(canonicalize-path
(string-append (dirname (current-filename)) "/../../my")))
(define-command (guix-hello . args)
(category plumbing)
(synopsis "hello world")
(begin
(format #t "hello~%")
(format #t "path: ~s~%" (my-path))
(add-to-load-path (my-path))
(format #t "load-path: ~%")
(for-each (lambda (path)
(format #t " ~s~%" path))
%load-path)
(for-each (lambda (what)
(format #t "~s: ~s~%" what (%search-load-path what)))
(list "top" "sub" "module/sub"))))
my/top.scm:
(define-module (my top)
#:export (from-top))
(define (from-top)
(let ((here (current-filename)))
(format #t "top: ~s~%"
(string-append (dirname here) here))))
