Re: Creating local variation of match-theme

[Jack Hill <jackhill@jackhill.us>]

Hi,

It's been a few days, so I was wondering if anyone had thoughts on the 
following:

Best,
Jack

On Sun, 8 Dec 2019, Jack Hill wrote:

> Hi Guix,
>
> I'd like to create a local variation of the matcha-theme package with one of 
> the colors changed to suit my taste. Rather than make the change in my clone 
> of the git repository, which could then become outdated, I thought I would 
> try to make the change programatically as part of the package definition. I 
> decided to make my change in a snippet as part of the origin specification 
> because that seemed to logically fit with what I was trying to do (build a 
> package with modified source) and because matcha-theme uses the trivial build 
> system, which I don't believe has the concept of phases, so it wasn't clear 
> how I would add a phase to make my change during the build. I came up with 
> the following package definition:
>
> ```
> (package
>  (inherit matcha-theme)
>  (source (origin
>            (inherit (package-source matcha-theme))
>            (modules '((guix build utils)))
>            (snippet
>              '(begin
>                 (substitute* (find-files "." "\\.css$")
>                   (("abb9b6") "859900"))))))
>  (synopsis "jackhill's version of the matcha-theme"))
> ```
>
> Unfortunately, after building my modified source tarball correctly, the 
> package build fails. I believe this is because matcha-theme's 
> trivial-build-system recipe expects a source checkout and not a tarball, and 
> doesn't have the logic to expand the tarball that, e.g., the gnu-build-system 
> provides.
>
> The build log contains the following:
>
> ```
> @ build-started 
> /gnu/store/rqx5yqh4ncj02rxzfwvp9jcqv9dk8l1g-matcha-theme-2019-11-02.drv - 
> x86_64-linux 
> /var/log/guix/drvs/rq//x5yqh4ncj02rxzfwvp9jcqv9dk8l1g-matcha-theme-2019-11-02.drv.bz2 
> 28285
> Backtrace:
>           4 (primitive-load "/gnu/store/j01a49zzlrn7fyr2x7ibxyqsph5?")
> In ice-9/eval.scm:
>   191:35  3 (_ #f)
>    619:8  2 (_ #(#(#(#(#(#<directory (guile-user) 7f?> ?) ?) ?) ?) ?))
> In 
> /gnu/store/ygivy1fvr7gbyva4z22b7vzzps1krbq5-module-import/guix/build/utils.scm:
>   343:27  1 (_ "/gnu/store/ajbvkiw30mmfhj8mpjfyvnxpjl0ycj07-matcha?" ?)
> In unknown file:
>           0 (copy-file "/gnu/store/ajbvkiw30mmfhj8mpjfyvnxpjl0ycj0?" ?)
>
> ERROR: In procedure copy-file:
> In procedure copy-file: Is a directory
> `/gnu/store/ajbvkiw30mmfhj8mpjfyvnxpjl0ycj07-matcha-theme-2019-11-02.tar.xz' 
> -> `/tmp/guix-build-matcha-theme-2019-11-02.drv-0'
> builder for 
> `/gnu/store/rqx5yqh4ncj02rxzfwvp9jcqv9dk8l1g-matcha-theme-2019-11-02.drv' 
> failed with exit code 1
> @ build-failed 
> /gnu/store/rqx5yqh4ncj02rxzfwvp9jcqv9dk8l1g-matcha-theme-2019-11-02.drv - 1 
> builder for 
> `/gnu/store/rqx5yqh4ncj02rxzfwvp9jcqv9dk8l1g-matcha-theme-2019-11-02.drv' 
> failed with exit code 1
> ```
>
> For reference, matcha-theme's builder is:
>
> ```
> (arguments
>     '(#:modules ((guix build utils))
>       #:builder
>       (begin
>         (use-modules (guix build utils))
>         (let* ((out (assoc-ref %outputs "out"))
>                (source (assoc-ref %build-inputs "source"))
>                (bash (assoc-ref %build-inputs "bash"))
>                (coreutils (assoc-ref %build-inputs  "coreutils"))
>                (themesdir (string-append out "/share/themes")))
>           (setenv "PATH"
>                   (string-append coreutils "/bin:"
>                                  (string-append bash "/bin:")))
>           (copy-recursively source (getcwd))
>           (patch-shebang "Install")
>           (mkdir-p themesdir)
>           (invoke "./Install" "-d" themesdir)
>           #t))))
> ```
>
> This leaves me with two questions:
>
> How should I accomplish what I want to do (change one of the colors in 
> matcha-theme for local use)?
>
> If I am right about trivial-build-system (that it makes it more difficult to 
> create modified packages compared to other build systems), should we try to 
> avoid using it in gnu/packages to ensure people have the easiest time 
> exercising their software freedom?
>
> Best,
> Jack
>
>