Re: Packages grow, no longer fit on a 💾

[Katherine Cox-Buday <cox.katherine.e@gmail.com>]

John Kehayias <john.kehayias@protonmail.com> writes:

>>> Efraim Flashner <efraim@flashner.co.il> skribis:
>>>
>>> I've made some progress on LLVM and I think I have a working LLVM
>>> that can be used as an input for mesa.

This is awesome! Thank you Efraim!

> I don't think there were any errors in building mesa with older LLVM,
> but on current hardware (unfortunately brings in non-free
> considerations) this was necessary. I believe this is the summary:
> <https://www.phoronix.com/news/LLVM-15-Branched>

I can confirm that 3D acceleration would not work until LLVM-15 was
used. I don't understand the entire rendering pipeline anymore, but I
think it had something to do with Vulkan.

> Props to katco on IRC for going through some long building and
> debugging to track this down.

Thanks, John!

Part of the reason this was difficult to test (aside from having to
discover the LLVM part) was discovering that the XORG_DRI_DRIVER_PATH
environment variable wasn't being set correctly despite doing package
rewriting to use a different version of Mesa.

I ended up doing this:

--8<---------------cut here---------------start------------->8---
(define-public (xorg-with-mesa xorg-server mesa)
  "Returns an xorg-server package which will wrap the call to Xorg to include the
correct XORG_DRI_DRIVER_PATH for the mesa package provided."
  (package
   (inherit xorg-server)
   (arguments
    (substitute-keyword-arguments
     (package-arguments xorg-server)
     ((#:phases child-phases '%standard-phases)
      #~(modify-phases #$child-phases
                       (add-after 'install 'wrap
                                  (lambda* (#:key outputs #:allow-other-keys)
                                    (let* ((out (assoc-ref outputs "out"))
                                           (bin (string-append out "/bin"))
                                           (xorg (string-append bin "/Xorg")))
                                      (wrap-program xorg
                                                    '("XORG_DRI_DRIVER_PATH" ":" = (#$(file-append mesa "/lib/dri")))))))))))))
--8<---------------cut here---------------end--------------->8---

But something like this (I'm sure I've gotten the gexps wrong) would have been made it much easier:

--8<---------------cut here---------------start------------->8---
diff --git a/gnu/services/xorg.scm b/gnu/services/xorg.scm
index 5f073d05d3..d626e87073 100644
--- a/gnu/services/xorg.scm
+++ b/gnu/services/xorg.scm
@@ -196,7 +196,9 @@ (define-record-type* <xorg-configuration>
   (server           xorg-configuration-server     ;file-like
                     (default xorg-server))
   (server-arguments xorg-configuration-server-arguments ;list of strings
-                    (default %default-xorg-server-arguments)))
+                    (default %default-xorg-server-arguments))
+  (mesa             xorg-configuration-mesa ; package
+                    (default mesa)))
 
 (define (xorg-configuration->file config)
   "Compute an Xorg configuration file corresponding to CONFIG, an
@@ -362,7 +364,7 @@ (define* (xorg-wrapper #:optional (config (xorg-configuration)))
   (define exp
     ;; Write a small wrapper around the X server.
     #~(begin
-        (setenv "XORG_DRI_DRIVER_PATH" (string-append #$mesa "/lib/dri"))
+        (setenv "XORG_DRI_DRIVER_PATH" (string-append #$(xorg-configuration-mesa config) "/lib/dri"))
         (setenv "XKB_BINDIR" (string-append #$xkbcomp "/bin"))
 
         (let ((X (string-append #$(xorg-configuration-server config) "/bin/X")))
--8<---------------cut here---------------end--------------->8---

--
Katherine