Re: simplest package definition?

[Alex Kost <alezost@gmail.com>]

Alex Kost (2016-08-25 11:19 +0300) wrote:

> John J Foerch (2016-08-25 04:07 +0300) wrote:
>
>> Hello Guix,
>>
>> What is the simplest possible package definition, to install a single
>> shell script?  If possible, I would like to install it from the
>> directory in which I'm developing it, and the package definition would
>> also be in a file in this directory.
>
> So you have some dir and 2 files there: "my-shell-script" and
> "guix.scm", right?  If you don't care about shebang (I mean if you have
> "#!/bin/sh" in the script, it will not be changed to
> /gnu/store/.../bash), then you can use trivial-build-system.

I've found how to patch shebang staying inside trivial-build-system.
There is 'patch-shebang' procedure in (guix build utils) module, so all
is needed is to call it with the proper path (containing bash or another
shell you use).  So the following lines should be added:

> (use-modules

   (gnu packages bash)

>  (guix gexp)
>  (guix packages)
>  (guix build-system trivial))
>
> (let ((script-name "my-shell-script"))
>   (package
>     (name script-name)
>     (version "0.1")
>     (source (local-file (string-append (dirname (current-filename))
>                                        "/" script-name)))
>     (build-system trivial-build-system)
>     (arguments
>      `(#:modules ((guix build utils))
>        #:builder
>        (begin
>          (use-modules (guix build utils))
>          (let* ((bin-dir  (string-append %output "/bin"))
>                 (bin-file (string-append bin-dir "/" ,script-name)))

Add inside 'let':
                  (bash-bin (string-append (assoc-ref %build-inputs "bash")
                                           "/bin"))

>            (mkdir-p bin-dir)
>            (copy-file (assoc-ref %build-inputs "source") bin-file)

             (patch-shebang bin-file (list bash-bin))

>            (chmod bin-file #o555)))))

      (inputs `(("bash" ,bash)))

>     (home-page #f)
>     (synopsis "bla bla")
>     (description "More verbose bla bla")
>     (license #f)))

-- 
Alex