[stable build from source] Ubuntu 20.04 scintilla not found

Hi all,

I've just updated to Ubunutu 20.04 and the configure script of the
stable branch is failing to find qscintilla2-qt5. The error appears
here:

configure:71463: g++ -o conftest -fPIC -g -O2 -pthread -fopenmp -I/usr/include/x
86_64-linux-gnu/qt5/QtNetwork -I/usr/include/x86_64-linux-gnu/qt5 -I/usr/include
/x86_64-linux-gnu/qt5/QtPrintSupport -I/usr/include/x86_64-linux-gnu/qt5 -I/usr/
include/x86_64-linux-gnu/qt5/QtHelp -I/usr/include/x86_64-linux-gnu/qt5 -I/usr/i
nclude/x86_64-linux-gnu/qt5/QtWidgets -I/usr/include/x86_64-linux-gnu/qt5 -I/usr
/include/x86_64-linux-gnu/qt5/QtGui -I/usr/include/x86_64-linux-gnu/qt5 -I/usr/i
nclude/x86_64-linux-gnu/qt5/QtSql -I/usr/include/x86_64-linux-gnu/qt5 -I/usr/inc
lude/x86_64-linux-gnu/qt5/QtXml -I/usr/include/x86_64-linux-gnu/qt5 -I/usr/inclu
de/x86_64-linux-gnu/qt5/QtCore -I/usr/include/x86_64-linux-gnu/qt5 -fPIC -I/usr/
include/suitesparse   conftest.cpp -lQt5Network -lQt5PrintSupport
-lQt5Help -lQt5Widgets -lQt5Gui -lQt5Sql -lQt5Xml -lQt5Core
-lqscintilla2-qt5 >&5
/usr/bin/ld: cannot find -lQt5Network
/usr/bin/ld: cannot find -lQt5PrintSupport
/usr/bin/ld: cannot find -lQt5Help
/usr/bin/ld: cannot find -lQt5Widgets
/usr/bin/ld: cannot find -lQt5Gui
/usr/bin/ld: cannot find -lQt5Sql
/usr/bin/ld: cannot find -lQt5Xml
/usr/bin/ld: cannot find -lQt5Core
/usr/bin/ld: cannot find -lqscintilla2-qt5
collect2: error: ld returned 1 exit status

This is curious since it was compiling perfectly in 19.10, that is, my
system had all dependencies. And still has, accroding to our wiki[1],
and to apt (all those modeules are installed).
All the include folders do exist.

Anynone with the same issue?

[1]: https://wiki.octave.org/Octave_for_Debian_systems
-- 
JuanPi Carbajal
https://goo.gl/ayiJzi

-----
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scholarship. The actual scholarship is the full software environment,
code and data, that produced  the  result.”
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