bug#51304: guix upgrade fails on qutebrowser

[Adam Maleszka via Bug reports for GNU Guix <bug-guix@gnu.org>]

On Th, Oct 21, 2021 at 22:00, Leo Famulari wrote:
> I think that should be enough, even for qtwebengine / Chromium!

Actually, I have been building qtwebengine@5.15.2 recently, and the
building process definitely took more RAM space then. The largest
increase in memory demand occurred at 73% --- as in the attached logs.

In my case, the building process was run on a computer with 16GB of RAM
and 16 threads. After adding a 30GB of swap space I was able to
successfully finish the build. Most of the time the memory usage was about
6GB of RAM, but at the critical moment --- almost 40GB.

I don't know if such a high demand can be solved by reducing the number
of threads. The huge difference in RAM usage indicates that the critical
moment just requires that much memory (too much of recursivity? too
complex operations?).

Spending 20GB of disk space (for swap) only to build a single library is
a laughable requirement. Such tasks should be carried out by the
substitution servers. Therefore, I believe the bug is not in the
qutebrowser package configuration, but the real problem is: why
substitutions aren't working with qtwebengine?