bug#40558: Modular TexLive "Insufficient extension fonts" and duplicate fonts

[Jelle Licht <jlicht@fsfe.org>]

Jelle Licht <jlicht@fsfe.org> writes:

> The eror message is:
> " ! Math formula deleted: Insufficient extension fonts."
[snip]
> AFAIK, and from looking at the full (and correctly working)
> texlive-texmf build, the cmex7.tfm in `euler' is not correctly build.
> My best guess is that this happens because cmex has both a mf file and a
> afm file in `guix build --source texlive-amsfonts'. The one 'built'
> using afm2tfm seems to be broken and/or not matching other metadata
> generated, as given by this example.


I have found a workaround for my immediate problem, but I'm not nearly
enough of a tex guru to foresee any issues my changes might cause.

After some trial and error that took longer than I'm willing to admit, I
have the following snippet:
 
--8<---------------cut here---------------start------------->8---
diff --git a/gnu/packages/tex.scm b/gnu/packages/tex.scm
index cd461314b5..363c7a318c 100644
--- a/gnu/packages/tex.scm
+++ b/gnu/packages/tex.scm
@@ -1108,7 +1108,7 @@ Taco Hoekwater.")
                  ;; convert the afm files instead.
                  (let ((build (string-append (getcwd) "/build-fonts/euler")))
                    (mkdir build)
-                   (with-directory-excursion "fonts/afm/public/amsfonts/"
+                   (with-directory-excursion "fonts/afm/public/amsfonts/euler"
                      (for-each (lambda (font)
                                  (format #t "converting afm font ~a\n" (basename font ".afm"))
                                  (invoke "afm2tfm" font
--8<---------------cut here---------------end--------------->8---

With this patch applied, I can make use of the modular texlive system
from the comfort of Emacs + org. It could be that there are other 'ghost
fonts' haunting up the place. 

The following...
--8<---------------cut here---------------start------------->8---
guix refresh -l texlive-amsfonts
Building the following 1438 packages would ensure 3202 dependent packages are rebuilt
--8<---------------cut here---------------end--------------->8---

makes me think this is very much a disruptive change. I'm not in a hurry
to get this upstreamed, but if anyone could reproduce the problem (and
my fix...), I would be more confident in pushing it.

- Jelle