INstructions for installing with Qt5+Py3 on Debian in INSTALL

INSTALL

@@ -335,15 +335,44 @@ code is compatible with PyQt5.
 
 You have been warned.
 
+  3.10. On Debian Linux
+  =====================
+
+We assume that you have the source code of QGIS ready and created a
+new subdirectory called `build` or `build-qt5` in it.
+
+    3.10.1. Install build dependencies
+    ==================================
+
+  apt-egt install git build-essential cmake flex bison pyqt5-dev qttools5-dev
+  qtpositioning5-dev libqt5svg5-dev libqt5webkit5-dev  libqt5gui5 libqt5scripttools5
+  qtscript5-dev libqca-qt5-2-dev grass-dev libgeos-dev libgdal-dev libqt5xmlpatterns5-dev
+  libqt5scintilla2-dev pyqt5.qsci-dev python3-pyqt5.qsci libgsl-dev txt2tags libproj-dev
+  libqwt-qt5-dev libspatialindex-dev pyqt5-dev-tools qttools5-dev-tools qt5-default
+  python3-future python3-pyqt5.qtsql python3-psycopg2
+
+Make sure that your build directory is completely empty when you enter the
+following command. Do never try to "re-use" an existing Qt4 build directory.
+If you want to use `ccmake` or other interactive tools, run the following
+command in the empty build directory once before starting to use the interactive
+tools.
 
-  3.10. On Fedora Linux
+  cmake -DENABLE_QT5=ON -DPORT_PLUGINS=ON
+
+If everything went ok you can finally start to compile. (As usual append a -jX
+where X is the number of available cores option to make to speed up your build
+process)
+
+  make
+
+  3.11. On Fedora Linux
   =====================
 
 We assume that you have the source code of QGIS ready and created a
 new subdirectory called `build` or `build-qt5` in it.
 
 
-    3.10.1. Install build dependencies
+    3.11.1. Install build dependencies
     ==================================
 
   dnf install qt5-qtwebkit-devel qt5-qtlocation-devel qt5-qttools-static