bug#26604: documentation: pdf generation is broken

[Andreas Enge]

Hello,

On Mon, Sep 28, 2020 at 09:57:43PM +0200, zimoun wrote:
> [env]$ make doc/guix.pdf

try this instead:
    make V=1 pdf
which will print what happens.

I have the monolithic texlive package in my profile and building the pdf
"almost worked":
...
doc/images/coreutils-size-map.png>
!pdfTeX error: /home/andreas/.guix-profile/bin/pdftex (file 
doc/images/coreutils-graph.png): reading image file failed
 ==> Fatal error occurred, no output PDF file produced!

It turns out there are a bunch of empty .png files in doc/images/, with
corresponding non-empty .dot files. I deleted them and installed graphviz
into my profile in the hope that "make pdf" would create the missing
.png files, but it does not.

However, the following "almost almost" worked:
- remove the empty .png files and install graphviz
- "make"
- "make pdf"
I obtained the English, German, French and Spanish pdf documentation, but
then a lot of complaints about unicode characters for the Russian
documentation (and "make doc/guix.zh_CN.pdf" also has unicode problems).

Andreas