Re: Help me create a janet-build-system

[Leo Prikler <leo.prikler@student.tugraz.at>]

Am Samstag, den 15.05.2021, 01:07 -0400 schrieb Jack Hill:
> Greetings Guix,
> 
> I'm working on creating a build system for Janet [0] modules. This is
> my 
> first time working with build systems, and while I have a much
> better 
> understanding than when I started, I still don't understand it fully.
> I've 
> attached my work in progress patches. The first five set the stage
> by 
> updating and improving our Janet package. Patch six adds the build
> system, 
> and patch seven adds an example package, janet-posix-spawn.
> 
> [0] https://janet-lang.org
> 
> Trying to build janet-posix-spawn results in:
> 
> ```
> jackhill@alperton ~/repos/guix [env]$ ./pre-inst-env guix build
> janet-posix-spawn
> The following derivations will be built:
>     /gnu/store/y1xpmfaqswcmiwzpc1bgak18rbw2k4ad-janet-posix-spawn-
> 0.0.1.drv
>     /gnu/store/w52ndznq3v42xxv4lfrpdlmwgn8r0f2x-module-import-
> compiled.drv
> building /gnu/store/w52ndznq3v42xxv4lfrpdlmwgn8r0f2x-module-import-
> compiled.drv...
> Backtrace:
> In system/base/compile.scm:
>       43:4 19 (call-with-output-file/atomic _ _ _)
> In ice-9/boot-9.scm:
>    1736:10 18 (with-exception-handler _ _ #:unwind? _ # _)
> In system/base/compile.scm:
>      59:11 17 (_)
>     155:11 16 (_ #<closed: file 7ffff69868c0>)
>     235:18 15 (read-and-compile #<input: guix/build/janet-build-
> syst?> ?)
>     183:32 14 (compile-fold (#<procedure compile-tree-il (x e opts)>)
> ?)
> In ice-9/boot-9.scm:
>     2806:4 13 (save-module-excursion _)
> In language/scheme/compile-tree-il.scm:
>      31:15 12 (_)
> In ice-9/psyntax.scm:
>    1241:36 11 (expand-top-sequence _ _ _ #f _ _ _)
>    1233:19 10 (parse _ (("placeholder" placeholder)) ((top) #(# # ?))
> ?)
>     285:10  9 (parse _ (("placeholder" placeholder)) (()) _ c&e (# #)
> #)
> In ice-9/eval.scm:
>     293:34  8 (_ #<module (#{ g32}#) 7ffff697ac80>)
> In ice-9/boot-9.scm:
>     3380:4  7 (define-module* _ #:filename _ #:pure _ #:version _ # _
> ?)
>    2565:24  6 (call-with-deferred-observers _)
>    3393:24  5 (_)
>     222:29  4 (map1 (((guix build gnu-build-system) #:prefix gnu:) #
> ?))
>     222:29  3 (map1 (((guix build utils)) ((guix utils))))
>     222:17  2 (map1 (((guix utils))))
>     3300:6  1 (resolve-interface (guix utils) #:select _ #:hide _ # _
> ?)
>    1669:16  0 (raise-exception _ #:continuable? _)
> 
> ice-9/boot-9.scm:1669:16: In procedure raise-exception:
> no code for module (guix utils)
> ```
> 
> What have I done wrong?
Your code imports (guix utils), but (guix utils) is not present within
the module closure present at build time.  
Did you mean (guix build utils)?

> More generally, I expect there are many ways I could improve the
> build system. What are they?
I know little about jpm, but in my opinion you ought to let the user
customize the flags passed on to jpm at least in the build target --
not so sure about check and install.  If janet-build-system allows some
degree of customization, consider also letting the user override the
test-target.

Regards,
Leo